volvo geometric tolerancing standard

Corporate Standard STD 5062,2E

Dept / Issued by 6857 Hans Lilja Issue 5 Established 2004-03 JOG Page 1(113)

Geometrical tolerances Indication, definitions and measuring principles

Orientation This issue differs from issue 4 in that the standard no longer applies to new design. For new designs, standards STD 112-0003, STD 112-0004 (Volvo Group), VCS 5062,29 and VCS 5062,39 (Volvo Car Corporation) shall be used.

This standard conforms to SS-ISO 1101-1984 with the following exceptions: The standard contains measuring principles and rules for measuring which are to be followed

when interpreting the requirements. This is not included in ISO 1101. A cylindrical tolerance zone is defined at angularity of a line. This is not done in ISO 1101. At Volvo, theoretically exact dimensions need only be framed if there is risk of misinterpretation.

According to ISO 1101, the values shall always be framed. The standard contains rules for the evaluation of abstract (unreal) features. This is not included in

ISO 1101. The rule stating that a negative deviation of 0,01 x the length may be deducted from the extension

of the toleranced feature is not included in ISO 1101. The fact that tolerance on profile of any line and tolerance on profile of any surface can be

specified in relation to datums is in this standard shown under positional tolerances and is then called position of any profile and position of any surface respectively. ISO 1101 states only that tolerance on profile of any line and tolerance on profile of any surface can be specified in relation to datums.

Contents 1 Scope and field of application 2 General 2.1 Definition of tolerance zone 2.2 Toleranced feature 2.3 Tolerance zone form 2.4 Form of toleranced feature within tolerance zone 2.5 Applicability of tolerance along feature 2.6 Datum feature 2.7 Form deviations of datum features 2.8 Establishing size of form deviation and extension of toleranced feature 2.9 Establishing form deviation of circular and cylindrical features 2.10 Measuring principles and rules for measuring 3 Symbols 4 Evaluation of abstract (unreal) features 5 Tolerance frame 5.1 Data in the tolerance frame 5.2 Symbol for number of features 5.3 Supplementary requirement 5.4 More than one tolerance requirement 6 Toleranced feature 7 Tolerance zones 7.1 Tolerance extension 7.2 Direction of tolerance zone 7.3 Special direction of tolerance zone 7.4 Same tolerance value for more than one feature 7.5 Common tolerance zone

NOT FOR NEW DESIGN AS OF 2004-03-01 This standard is valid when there is a reference to it. Not for new design is only an indication to our design departments.


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8 Symbols for datums 8.1 Datum indicated by datum letter 8.2 Location of datum triangle 8.3 Datum indicated without datum letter 8.4 Sequence of datum letters 9 Restrictive specifications 9.1 Tolerance for a restricted length of the feature 9.2 Tolerance for the whole feature and restricted length of the feature 9.3 Tolerance for a restricted part of the feature 9.4 Datum applied to a restricted part of the feature 10 Theoretically exact dimensions 11 Projected tolerance zones 12 Maximum material principle 13 Definitions of tolerances 13.1 General 13.2 One type of tolerance may control several types of deviations 13.3 Graphical representation of tolerance zones 14 Detailed definitions of tolerances form tolerances 14.1 Straightness tolerance 14.2 Flatness tolerance 14.3 Circularity tolerance 14.4 Cylindricity tolerance 14.5 Profile tolerance of any line 14.6 Profile tolerance of any surface Orientation tolerances 14.7 Parallelism tolerance 14.8 Perpendicularity tolerance 14.9 Angularity tolerance Positional tolerances 14.10 Positional tolerance 14.11 Concentricity and coaxiality tolerance 14.12 Symmetry tolerance Run-out tolerances 14.13 Circular run-out tolerance 14.14 Total run-out tolerance 15 Reference on drawing

1 Scope and field of application The standard comprises principles of symbolisation and indication on technical drawings of toler-ances of form, orientation, position and run-out, and establishes the appropriate geometrical defini-tions. The term geometrical tolerances will be used in this standard as synonymous with these tolerances. Geometrical tolerances shall be indicated with respect to the function requirements. Manufacturing and inspection requirements may also influence the way in which geometrical tolerances are speci-fied. The indication of geometrical tolerances does not mean that a specific method for manufacture, measurement and inspection is required. This standard also contains measuring principles and certain rules for measurement which are not included in ISO 1101.


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When specifying requirements for parts within thin-walled product design, that is thin-walled parts mainly included in the body, exterior and interior, as well as other parts for which the master location system in accordance with STD 5026,2 is used, STD 5026,25 Geometrical tolerances for thin-walled product design shall be applied.

2 General

2.1 Definition of tolerance zone A geometrical tolerance for a feature defines the tolerance zone within which this feature shall be contained.

2.2 Toleranced feature A feature is a specific characteristic of a part, such as axis, median plane, surface, hole, recess or profile.

2.3 Tolerance zone form Depending on the characteristic which is to be toleranced and the way in which it is indicated, the tolerance zone is one of the following:

the area within a circle

the area between two concentric circles

the area between two equidistant lines or between two parallel straight lines

the space within a cylinder

the space between two coaxial cylinders

the space between two equidistant surfaces or two parallel planes

the space within a bent pipe

2.4 Form of toleranced feature within tolerance zone The toleranced feature may be of any form or orientation within the tolerance zone in question unless a more restrictive indication is given, for example by an explanatory note.

2.5 Applicability of tolerance along feature The tolerance applies to the entire length or surface of the toleranced feature unless otherwise indi-cated.

2.6 Datum feature The datum feature is an actual feature of a part. It is used to determine the location of a datum. See STD 5062,15,

2.7 Form deviations of datum features Geometrical tolerances which are assigned to features related to a datum do not restrict the form deviations of the datum feature itself. The form of the datum feature shall be sufficiently accurate for its purpose and it may therefore be necessary to specify tolerances of form for the datum feature.


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2.8 Establishing size of form deviation and extension of toleranced feature The straightness or flatness of an individual toleranced feature is deemed to be correct when the distance from its individual points to a superimposed line or surface of ideal geometrical form is equal to or less than the value of the specified tolerance. The orientation of the ideal line or surface shall be chosen so that the maximum distance (h1 in figure 1) between it and the actual profile or surface of the feature concerned is the least possible value.

Fig 1

Possible orientations of the line or surface: A1 - B1 A2 - B2 A3 - B3

Corresponding distance: h1 h2 h3

In the case of figure 1: h1 < h2 < h3

Therefore, the correct orientation of the ideal line or surface is A1 - B1. The distance h1 is to be equal to or less than the specified tolerance.

The above rule leads to the least possible rejection when the feature in question is checked.

When establishing the size of the form deviation in accordance with the tolerance definition, the use of a superimposed line/surface is presumed. This requires extensive and time-consuming verificat-ion. A simpler method is the use of a tangent line/surface as below. This leads to a greater rejection which, however, shall be compared with the lower cost for verification.

When measuring is carried out from a tangent line/surface, we get deviations that are equal to or greater than those obtained when measuring from superimposed line/surface.

Determination of the form deviation from a tangent line/surface shall be applied when a measuring principle indicating this is specified on the drawing.


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Normally, tangent line/surface gives the position which the feature assumes when fixed. See figure 2. If the feature has form deviations of such a nature that its surface is convex and allows a stable position by means of two or more tangent surfaces, the determination may be carried out from any-one of the tangent surfaces unless otherwise indicated.

Fig 2

When determining the extension of the toleranced feature, the negative deviation for measuring range" 0,01xL, where L is the extension of the toleranced feature, shall always be deducted. See figure 3. A positive deviation, e.g. a burr, shall always be included.

Fig 3

2.9 Establishing form deviation of circular and cylindrical features For the definition of circularity and cylindricity, the location of the two concentric circles or coaxial cylinders shall be chosen so that the radial distance between them is the least possible value. Example:

Fig 4

Possible location of the centre of the two concentric circles or the axes of the two coaxial cylinders and their minimal radial distance.

Centre (C1) for A1 locates two concentric circles or two coaxial cylinders.

Centre (C2) for A2 locates two concentric circles or two coaxial cylinders with minimal radial distance.


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Corresponding radial distance: r1 r2

In the case of figure 2: r2 < r1

Therefore, the correct location of the two concentric circles or the two coaxial cylinders is the one designated A2. The radial distance r2 should then be equal to or less than the specified tolerance.

2.10 Measuring principles and rules for measuring By measuring principles is in this standard meant basic methods to measure compliance with the tolerance requirement. The measuring principle shall always be indicated on the drawing. The measuring principles are designated by Roman numerals and are indicated in the last box of the tolerance frame. See example in figure 5.

0,1 A II

Fig 5

Section 14 illustrates the available measuring principles by describing the measuring methods. It should be noted that the measuring principles can be met with measuring methods and equipment other than those shown in the figures.

A measuring principle designated by a Roman I complies with the requirements specified in the tol-erance definition. If no measuring principle is indicated, measuring principle I shall be applied. All measuring principles with higher numbers, that is, II, III, IV and so on, are simplified measuring principles and do not comply with the requirements specified in the tolerance definition. For these measuring principles there is no relation between the degree of simplification and the designation of the measuring principle, that is, measuring principle IV can be closer to the tolerance definition than measuring principle II is. For interpretation of an indicated measuring principle see section 14 where an explanation is given under the relevant tolerance type. The measuring principles are established for each tolerance type, e.g., measuring principle II for one tolerance type need not have the same meaning when applied to another type of tolerance.

Measuring principle shall be chosen with a view to the function requirements. Manufacturing and inspection requirements can also influence the selection of measuring principle.

The specification of a specific measuring principle means that the measuring principle in question is decisive for the interpretation of the tolerance requirement.

A requirement with maximum material principle indicated on the drawing by means of an means that the tolerance definition is modified with respect to the tolerance zone. The specified measuring principle then applies to this modified tolerance zone.

Where the text to the measuring principle runs Checked with, e.g., a function gauge, the require-ment shall be checked in such a way that a requirement which is checked without a function gauge and passed would also pass if it were to be checked with a function gauge.

When the text to the measuring principle runs for the required number of sections/generators/ points this means that measuring shall be carried out in so many sections that it is highly probable that the tolerance will not be exceeded when measuring in other sections is carried out.

2.10.1 Measuring force When measuring with indicating measuring device, the measuring force shall be max 1 N.

For soft objects, contactless measuring is recommended.

When the measuring force influences the measuring result, this shall be re-calculated with a view to this. Variations in the measuring force during the measuring shall also be taken into consideration.


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2.10.2 Anvil size Depending on the form of the measuring surface, the anvil shall be selected from the table below, unless otherwise indicated.

Table 1 Form of surface to be measured

Anvil radius in mm

Radius of surface to be measured in mm

Flat and convex surfaces

2,5 or flat anvil

Concave surfaces

2,5 0,5

above 10 up to and incl. 10

When soft objects are checked with a sensing anvil, it is recommended that the anvil is flat and has a circular or square cross-section. Diameter of anvil (side) B = 1 + 0,005 x L, where L is the greatest length in mm of the measured surface. See figure 6. Measuring pressure = 0,01 N/mm2.

Fig 6


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3 Symbols

Table 2 Symbols for toleranced characteristics Features and tolerances

Toleranced characteristic

Symbol Section

Single features Form tolerances

Straightness 14.1

Flatness

14.2

Circularity

14.3

Cylindricity

14.4

Profile of any line 1)

14.5

Profile of any surface 2)

14.6

Related features

Orientation tolerances

Parallelism

14.7

Perpendicularity

14.8

Angularity

14.9

Positional tolerances

Position

14.10

Position of any profile 1)

14.10

Position of any surface 2)

14.10

Concentricity and coaxiality

14.11

Symmetry 14.12

Run-out tolerances

(Circular) run-out

14.13

Total run-out 14.14

1) Refers to bent lines 2) Refers to curved surfaces


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Table 3 Additional symbols Description Symbol Section

Toleranced feature indication direct

6

by letter A

7.4

Datum indication direct

8.3

by letter A

8.1

Datum target

A12

See STD 5062,15

Theoretically exact dimension 50

10

Projected tolerance zone

11

Maximum material principle

12

Measuring principle I, II, III etc. 2.10 and 14


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Table 4 Symbols used in section 14 to illustrate how the

measuring principles shall be interpreted

Symbol Interpretation

Measuring plane, auxiliary plane (surface plate)

Fixed support

Adjustable support

Continuous linear traverse

Intermittent linear traverse

Continuous traverse in several directions

Continuous turning

Intermittent turning

Rotation

Indicating measuring instrument (dial indicator)

Measuring stand with indicating measuring instrument Symbols for measuring stands can be drawn in different ways in accordance with the verification equipment used


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4 Evaluation of abstract (unreal) features Evaluation of features in accordance with the table shown below is theoretical. For practical reasons, one often departures from the theoretical evaluation when establishing a feature. In many cases an expanding or slightly tapered mandrel can be used instead of an inscribed cylindrical mandrel when aligning a feature against the real cylinder surface of a hole. A shrink mandrel (tensioning sleeve) can be utilized as circumscribed cylinder for a shaft.

Table 5 Abstract feature Evaluated as: Figure

Centre of the cross-section of a hole

Centre of the largest inscribed circle

Centre of the cross-section of an axis

Centre of the smallest circumscribed circle

Axis of a hole The axis of the largest

inscribed cylinder

Axis of a shaft The axis of the

smallest circumscribed cylinder

Median plane of a feature The median plane

determined by the two contact surface


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5 Tolerance frame

5.1 Data in the tolerance frame The tolerance requirements shall be indicated in a rectangular frame which is divided into two or more compartments. The following shall be indicated in the compartments from left to right (see figures 7, 8, 9 and 10):

the symbol for the characteristic which is to be toleranced.

the tolerance value in the unit used for linear dimensions. If the tolerance zone is circular or cylindrical, the sign shall be indicated before the tolerance value.

letter(s) for datum(s) when the toleranced feature is specified in relation to one or more datums.

the established measuring principle.

0,1

0,1 A

0,1 A C B

IV

Fig 7 Fig 8 Fig 9 Fig 10

5.2 Symbol for number of features When the feature applies to more than one feature, e.g. six holes, this shall be indicated above the tolerance frame by 6x. See figure 11.

6x 0,1

Fig 11

5.3 Supplementary requirement Indications qualifying the form of the feature within the tolerance zone shall be written near the tol-erance frame and shall be connected to this by means of a leader line. See figures 12 and 13.

0,3

EJ KONVEX / NOT CONVEX 0,1 A

EJ KONVEX / NOT CONVEX

Fig 12 Fig 13

5.4 More than one tolerance requirement If it is necessary to specify more than one tolerance characteristic for a feature, the tolerance speci-fications shall be given in separate tolerance frames one under the other. See figure 14.

0,1

0,6 B

Fig 14

6 Toleranced feature The tolerance frame shall be connected to the toleranced feature by means of a leader line termi-


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nating with an arrowhead in the following way.

on the outline of the feature or on an extension of the outline (but clearly separated from dimension lines) when the tolerance refers to the line or surface itself. See figures 15 and 16.

on a leader line connected to the relevant surface by means of a point. See figure 17.

Fig 15 Fig 16 Fig 17

as an extension of the dimension line, when the tolerance refers to the axis or median plane of the feature. See figures 18, 19 and 20.


on the axis, when the tolerance applies to the common axis or the median plane of all or certain selected features. See figures 21, 22 and 23.

An indication in accordance with figures 21, 22 and 23 may only be used when it is fully clear which feature(s) is/are toleranced.

NOTE: In the examples illustrated by figures 22 and 23, maximum material principle is recommended on the toleranced features if the function so permits. This shall be done to make it possible to check the requirements from an economical point of view.



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For parts where the function of the toleranced feature and datum feature is the same, the tolerance requirement shall be indicated as shown in figure 24. Previously, such a tolerance requirement was indicated in accordance with figure 25.

Fig 24 Fig 25

7 Tolerance zones

7.1 Tolerance extension The tolerance zone extends (unless otherwise indicated) in the direction of the arrow of the leader line joining the tolerance frame to the tolerance feature. See figures 26, 27 and 28. Figure 27 and 28 shows more explicitly that the extension of the tolerance zone is in the same orientation as an imagined plane through A and B. Indication in accordance with figure 27 shall therefore be applied.

If the tolerance value is preceded by the sign , the tolerance zone is circular or cylindrical and, in that case, the direction of the arrow is unimportant. See figure 29 which shows a cylindrical tolerance zone.

GAUGING

Fig 26 Fig 27 Fig 28 Fig 29


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7.2 Direction of tolerance zone In general, the direction of the width of the tolerance zone (in each section) is normal to the specified geometry of the part. See figures 30 and 31.

Fig 30 Fig 31

7.3 Special direction of tolerance zone The direction of the tolerance zone shall be indicated when desired not normal to the specified geo-metry of the part. See figures 32 and 33.

Fig 32 Fig 33

7.4 Same tolerance value for more than one feature When the same tolerance value applies to more than one single feature with individual tolerance zones, this can be indicated as shown in figures 34 and 35. Where it cannot be misinterpreted as to which features are referred to, indication may be in accordance with figure 11.

Fig 34


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Fig 35

7.5 Common tolerance zone By common tolerance zone is meant that all specified features shall be within the tolerance zone indicated.

Such a requirement shall be indicated with the phrase "common tolerance zone above the tolerance frame in accordance with figures 36 and 37.

Where it cannot be misinterpreted as to which features are concerned, no arrows are needed for each feature but indication may be as shown in figure 11.

Fig 36

Fig 37


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8 Symbols for datums

8.1 Datum indicated by datum letter When a toleranced feature is related to a datum, this is generally shown by datum letter(s). The same letter which defines the datum is repeated in the tolerance frame. The datum is represented by a capital letter enclosed in a square which is connected to a filled datum triangle. See figure 38. In SS-ISO 1101 the datum triangle may be unfilled as shown in figure 39.

Fig 38 Fig 39

8.2 Location of datum triangle The datum triangle with the datum letter shall be placed:

on the outline of the feature or on an extension of the outline but clearly separated from the dimension line when the line or the plane constitutes the datum. See figure 40.

Fig 40

as an extension of the dimension line when the datum is the axis or median plane. See figures 41, 42 and 43.

NOTE - If there is insufficient space for two arrowheads on the dimension line, one of them may be replaced by the datum triangle. See figures 42 and 43.


on the axis or median plane when the datum is:

a) the axis or median plane of a single feature (for example a cylinder).

b) the common axis or plane formed by two features. See figures 44 and 45.


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If a datum is indicated directly on the axis as shown in figures 44 and 45, it must be clear which fea-tures constitute the datum.

Fig 44 Fig 45

If a surface in the drawing plane is chosen as a datum, a leader line that terminates with a point on the datum shall be used. See figure 46.

Fig 46

8.3 Datum indicated without datum letter If the tolerance frame can be directly connected to the datum by a leader line, the datum letter may be omitted as shown in figures 47 and 48.

Fig 47 Fig 48

8.4 Sequence of datum letters A single datum is identified by one (1) datum letter. See figure 49.

A datum formed by two features is identified by two datum letters separated by a hyphen. See figure 50.

A

A-B

Fig 49 Fig 50

If the sequence of two or more datums is of importance, the datum letters shall be placed in different compartments as shown in figure 51, where the sequence from left to right shows the order of priority.


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If the sequence of two or more datums is of no importance, for example in connection with maximum material principle on several datum features, the datum letters shall be indicated in the same compartment. See figure 52.

A CB

A BM M

Fig 51 Fig 52

In those cases unsatisfactory guidance is obtained with the datum features, alignment against another feature has to be carried out. For the part shown in figure 53 datum features B and C give an unsatisfactory guidance. To get an unambiguous alignment, the part must be aligned with A.

Fig 53

9 Restrictive specifications

9.1 Tolerance for a restricted length of the feature If the tolerance applies to a restricted length within the total length of the feature, the value of the restricted length shall be indicated in the tolerance frame after the tolerance value and separated from it by an oblique line. See figure 54. The requirement applies to any measuring length within the total length.

In the case of a surface, the same indication shall be used. This means that the tolerance applies to all lines of the specified length in any position and any direction on the surface. See figure 54. The restricted length shall be found in all directions on the surface.

0,01/100 A

Fig 54

9.2 Tolerance for the whole feature and restricted length of the feature If a smaller tolerance of the same tolerance type is added to the tolerance on the whole feature, but restricted over a limited length, the smaller tolerance shall be indicated below the tolerance for the whole feature. See figure 55.

0,1A

0,05/200

Fig 55


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9.3 Tolerance for a restricted part of the feature If the tolerance applies to a restricted part of the feature only, this shall be indicated as shown in figure 56.

Fig 56

If a surface in the drawing plane is to be toleranced, a leader line that terminates with a point on the toleranced surface shall be used. See figure 57.

Fig 57

9.4 Datum applied to a restricted part of the feature If the datum is applied to a restricted part of the datum feature, this shall be indicated as shown in figure 58.

Fig 58


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10 Theoretically exact dimensions If a tolerance of form, orientation or position is specified for a feature, the dimension determining the theoretically exact form, orientation or position respectively must not be toleranced. The corre-sponding actual dimensions may only vary by the tolerances of form, orientation or position specified within the tolerance frame.

SS-ISO 1101 specifies that dimensions determining the theoretical profile, surface, angle or position shall be framed. At Volvo the general practice shall be to frame these dimensions only when there is risk of interpreting them as dimensions to which a general tolerance on the drawing applies. In such a case, the dimensions shall be framed by rectangles as shown in figures 59 and 60.

Fig 59 Fig 60

11 Projected tolerance zones In some cases, the tolerance of orientation and position shall apply not to the feature itself but to the external projection of it. Such projected tolerance zones shall be indicated by the symbol

( = projected). See figure 61.

Fig 61


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12 Maximum material principle If maximum material principle is permitted, this shall be indicated by the symbol placed after:

the tolerance value (see figure 62)

the datum letter (see figure 63)

or both (see figure 64)

depending on whether the maximum material principle is to be applied to the toleranced feature, to the datum feature or to both of these features.

0,04 A M

0,04 A M

0,04 A M M


If the datum is not identified by a letter, maximum material principle for the datum shall be indicated in the third compartment of the tolerance frame. See figures 65 and 66.

0,04 M

0,04 M M

Fig 65 Fig 66


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13 Definitions of tolerances

13.1 General The tolerance zones for the various geometrical tolerances are defined in the following pages. In all the illustrations of the definitions only those which concern the definition in question are shown.

13.2 One type of tolerance may control several types of deviations Where required for functional reasons, one or more characteristics may be toleranced to define the geometrical accuracy of a feature. When the geometrical accuracy is defined by certain types of tolerance, other deviations will in some cases be controlled by the tolerance indicated (for example, straightness deviation is limited by parallelism tolerance when inspecting in accordance with the measuring principles that meet the requirements of the tolerance definition). Thus it will rarely be necessary to indicate tolerances for all these characteristics, since other deviations will be included in the tolerance zone defined by the symbol used.

13.3 Graphical representation of tolerance zones For some tolerance zones (for example, straightness of a generator and parallelism for a line in one direction) there are two possible methods of graphical representation:

by two parallel planes a distance t apart. See figure 67 by two parallel lines a distance t apart. See figure 68

Fig 67 Fig 68

There is no difference in the meaning of the two representations (such a tolerance does not restrict the deviation in any direction perpendicular to the tolerance arrow). The simpler method as shown in figure 68 is normally used in this standard.


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14 Detailed definitions of tolerances form tolerances

Form tolerances

14.1 Straightness tolerance The tolerance zone when projected in a plane is limited by two parallel straight lines a distance t apart. See figure 69.

The tolerance zone is applicable to generators, edges and specified sections in surfaces. It is usually possible to specify a measuring principle which permits measuring from a tangent surface (line), something which simplifies inspection.

Fig 69 Fig 70

The tolerance zone is limited by a cylinder of diameter t if the tolerance value is preceded by the sign . See figure 70. The cylindrical tolerance zone may be applied, for example, to solids of revolution in connection

with maximum material principle.

If maximum material principle is not permitted, the requirement for straightness of an axis should, if possible from a functional point of view, be replaced by a requirement for straightness of a generator.

Indication and interpretation Measuring principle

I

Fig 71 Fig 72

Each generator on the cylinder surface shall be contained between two parallel lines 0,1 apart in a plane containing the axis.

Two points on a generator, as far apart as possible, shall be aligned to the same distance from the measuring plane.

The generator shall be measured at the required number of measuring points.c. The measuring results shall be recorded in a diagram and the straightness deviation of the generator shall be evaluated.

The measuring shall be carried out on the required number of generators.d.


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I

Fig 73 Fig 74

Each generator on the cylinder surface shall be contained between two parallel lines 0,1 apart in a plane containing the axis.

The measuring shall be repeated on the required number of generators. The values obtained for each generator measured shall be recorded in a diagram and evaluated.

The maximum variation in distance on an individual generator constitutes the straightness deviation of the generator.

NOTE: The superimposed line is not obtained until at the evaluation.

V

Fig 75 Fig 76

Each generator on the cylinder surface shall (when checked in accordance with the adjacent measuring principle) be contained between two parallel lines 0,1 apart in a plane containing the axis.

Two points on a generator, as far apart as possible, shall be aligned to the same distance from the measuring plane.

The generator shall be measured at the required number of measuring points c The measuring shall be carried out on the required number of generators d The largest difference obtained between max and min readings on an individual generator shall be regarded as the straightness deviation of the generator.

The difference between max and min readings is always greater than or equal to the deviation which would have been obtained if measuring had been carried out in accordance with the definition of the tolerance (measuring principle I).


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VI

Fig 77 Fig 78

Each generator on the cylinder surface shall (when checked in accordance with the adjacent measuring principle) be contained between two

The check shall be carried out on the required number of generators.

The measuring shall be carried out on the required number of generators.

parallel lines 0,1 apart in a plane containing the axis. The maximum variation in distance on an individual generator shall be regarded as the straightness deviation

of the generator.

NOTE: For convex lines not giving a stable position, the measuring object shall be guided against the measuring plane in such a way that the measured deviation becomes a minimum (superimposed line).

The deviation measured is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the definition of the tolerance (measuring principle I).

I

Fig 79 Fig 80

Each line on the upper surface parallel to the plane of projection in which the indication is shown, shall be contained between two parallel lines 0,2 apart. See figure 83.

Any portion of lengths 100 of any line of the upper surface, parallel to the plane of projection in which the indication is shown, shall be contained between two parallel lines 0,1 apart. See figure 83.

The measuring shall be carried out on the required num-ber of lines. The values obtained for each line shall be recorded in a diagram and evaluated.

The maximum deviation in distance on an individual line constitutes the straightness deviation of the line.

NOTE: The superimposed line is not obtained until at the evaluation.


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VI

Fig 81 Fig 82

Each line on the upper surface, parallel to the plane of projection, shall (when checked in accor-dance with the adjacent measuring principle) be

The check shall be carried out on the required number of lines.

The measuring shall be carried out on the required number of lines.

contained between two parallel lines 0,2 and 0,1 apart respectively. See figure 83.

The maximum variation in distance obtained shall be regarded as the straightness deviation of the line.

The straightness deviation shall be measured both in the longitudinal and in the transverse direction

NOTE: For convex lines not giving a stable position, the measuring object shall be guided against the measuring plane in such a way that the measured deviation becomes a minimum (superimposed line ).

The deviation measured is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the defi-nition of the tolerance (measuring principle I).

The surface shall in each section be contained between two parallel lines a distance t apart. The lines shall in their turn be parallel to the projection in which the tolerance is indicated.

Fig 83


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I

Fig 84 Fig 85

The axis of the part shall be contained within a cylinder of diameter 0,1 + maximum material principle.

Checked with, e.g., a function gauge.

I

Fig 86 Fig 87

The axis common to the two holes (D1 and D2) shall be contained within a cylinder of diameter 0,1 + maximum material principle.


II

Fig 88 Fig 89

The axis of the part shall (when checked in accordance with the adjacent measuring principle) be contained within a cylinder of diameter 0,1 + maximum material principle.



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I

Fig 90 Fig 91

The axis of the part shall be contained within a cylinder of diameter 0,1.

The measuring object shall be clamped between two coaxial centres or corresponding which are parallel to the measuring plane.

The measuring shall be carried out along two generators opposite each other.

Half the difference in value between the dial indicators,

that is Ma Mb

2 for each point shall be recorded in a

diagram and the diagram shall be evaluated.

The required number of generators shall be measured and the largest straightness deviation in an individual section of the axis, constitutes the straightness deviation of the axis.

III

Fig 92 Fig 93

The axis of the part shall (when checked in accordance with the adjacent measuring principle) be contained within a cylinder of diameter 0,1.

The cylinder surface shall be measured in a radial section while being rotated one revolution. c. The measuring shall be repeated in the required number of sections. d. The maximum difference between max and min readings in the radial section with the largest difference between max and min readings shall be regarded as the straightness deviation.


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NOT FOR NEW DESIGN

IV

Fig 94 Fig 95

Interpretation, see measuring principle. Straightness for the axis of a cylinder surface.

The part shall be placed (in two 90 V-yokes) on two sections a distance b apart.

The cylinder surface shall be measured in a radial section while being rotated one revolution.

The measuring shall be repeated in the required number of sections.

Half of the maximum difference between max and min readings shall be regarded as the straightness deviation.


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14.2 Flatness tolerance The tolerance zone is limited by two parallel planes a distance t apart. See figure 96.

Fig 96


I

Fig 97 Fig 98

The median plane of the part shall be contained between two parallel planes 0,1 apart + maximum material principle.


(It shall be possible for the measuring object to pass through the gap)

I

Fig 99 Fig 100

The surface shall be contained between two paral-lel planes 0,1 apart.

The measuring object shall be placed on three supports, two adjustable and one fixed.

Three points on the surface as far apart as possible shall be aligned to the same distance from the measuring plane.

The surface shall be measured at the required number of points.

The difference between max and min readings shall be recorded in a level type diagram for evaluation.

Measuring with autocollimator is also referred to this measuring principle.

NOTE: The superimposed surface is not obtained until at the evaluation.


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NOT FOR NEW DESIGN

II

Fig 101

Interpretation, see measuring principle. Flatness.

Aligned and measured in accordance with figure 100.

The difference between max and min readings shall be regarded as the flatness deviation.

The difference obtained is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the defi-nition of the tolerance.


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III

Fig 102 Fig 103

The surface shall (when checked in accordance with the adjacent measuring principle) be con-tained between two parallel planes 0,1 apart.

The measuring object shall be placed on a measuring plane so that a stable position is obtained.

The measuring plane shall be of such dimensions that the entire measuring object is placed on this measuring plane when measuring is carried out.


The largest difference between max and min readings shall be regarded as the flatness deviation.

Note: For convex surfaces not giving a stable position, the measuring object shall be guided against the measur-ing plane in such a way that the deviation becomes a minimum.

III

Fig 104

A parallel shall be placed on the toleranced surface as a tangent plane.

The parallel shall be indicated in such a way that it is parallel to the measuring plane.

The parallel shall be removed and the toleranced surface measured in several directions.


The difference between max and min readings is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the definition of the tolerance (measuring principle I).


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IV

Fig 105 Fig 106

The surface shall (when checked in accordance with the adjacent measuring principle) be con-tained between two parallel planes 1 apart.

Measuring device with three fixed support points 2 x L apart shall be placed on the surface.

The dial gauge shall be placed in accordance with figure 106 where a is to be preferred.

L = 100 mm unless otherwise indicated.

The surface shall be measured at the required number of points by displacement of the measuring device.


This measuring principle means an undefined require-ment, but it often meets requirements from a practical point of view.

The difference obtained between max and min readings will depend on the different levels of the surface at which the support points happen to be placed when the measur-ing device is displaced.


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14.3 Circularity tolerance The tolerance zone in the considered plane is limited by two concentric circles a distance t apart. See figure 107.

A circularity tolerance is applicable to edges and sections. The function often permits the use of a measuring principle according to which three-point measurement or measuring of difference in diameter (two point measure-ment) may be applied.

Fig 107


I

Fig 108 Fig 109

The circumference of the edge shall be contained between two co-planar concentric circles a radial distance 0,1 apart.

Measuring device: Instrument for measuring variation in radius from a fixed centre.

The edge or the cylinder surface shall be measured in a radial section while being rotated one revolution

The measuring shall be repeated on the cylinder surface in the required number of sections.

The readings obtained shall be recorded in a polar dia-gram, one for each measuring section

Evaluation: The circularity deviation is the difference in radius between two concentric circles, one inscribed and the other circumscribed, where the difference between

Fig 110 their radii is the smallest possible. (MZC)

The circumference shall in each section be con-tained between two co-planar concentric circles a radial distance 0,1 apart.

NOTE: The measuring principle is applicable to in-ternal and external surfaces (holes and shafts).

The circularity deviation shall be determined in the section with the largest difference in radius.


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II

Fig 111 Fig 112

The circumference shall (when checked in accor-dance with the adjacent measuring principle) in each cross-section be contained between two co-planar concentric circles a radial distance 0,1 apart.

The axis of the measuring object shall be perpendicular to the measuring direction and axially fixed.

The cylinder surface shall be measured in a radial section while being rotated one revolution.


Half of the maximum difference between max and min readings in the measuring section having the largest reading difference shall be regarded as the circularity deviation.

Measuring shall be carried out in two different measuring devices, 90 and 120 respectively, whereby certain lobing is also checked.

III

Fig 113 Fig 114


The axis of the measuring object shall be perpendicular to the measuring direction and axially fixed.



Measuring shall be carried out in two different measuring devices, 90 and 120 respectively, whereby certain lobing is also checked.


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IV

Fig 115


Measured in accordance with figure 112 but only in a 120 measuring device.


No requirement concerning checking of lobing.

V

Fig 116


Measured in accordance with figure 114 but only in a 120 measuring device.




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VI

Fig 117 Fig 118


The axis of the measuring object shall be perpendicular to the measuring direction.

The cylinder surface shall be measured in a radial section by a number of two-point measurements.




The most common measuring method for checking circularity is a combination of the three-point and the two-point measurement systems and is indicated by one of the measuring principles II - V + VI.

Example: 0,2 II + VI


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14.4 Cylindricity tolerance The tolerance zone is limited by two coaxial cylinders a distance t apart. See figure 119.

Measuring the cylindricity in accordance with the tolerance definition (measuring principle I) is time-consuming and expensive and cannot be used for certain types of parts.

Fig 119

MEASURING PRINCIPLE I SHALL THEREFORE ONLY BE SPECIFIED WHEN INSPECTION IN ACCORDANCE WITH SIMPLIFIED MEASURING PRINCIPLES II-IV IS NOT PERMITTED FOR FUNCTIONAL REASONS. From the measuring point of view it may sometimes be suitable to indicate special tolerances for the straightness and circularity of the feature instead of cylindricity, if necessary supplemented with parallelism for opposite generators.


I

Fig 120 Fig 121

The toleranced surface shall be contained be-tween two coaxial cylinders a radial distance 0,1 apart.

Measuring device: Instrument for measuring variation in radius from a fixed centre. The principle is the same even if the measuring device is rotated. Measuring shall be carried out in the required number of radial sections from the same axis. Connected polar dia-grams and diagrams showing generator form in different axial sections are required for evaluation of the measur-ing results.

NOT FOR NEW DESIGN (Instead, straightness for the axis + maximum material principle for the same tolerance require-ment shall be indicated.)

I

Fig 122 Fig 123 The surface shall be cylindrical within 0,1 mea-sured on the radius t + permitted maximum mate-rial principle.

Cylindricity with max material principle for a cylinder surface. Measuring with a function gauge in accordance with Taylor's principle. Permissible cylindricity deviation is the difference between the diameter of the function gauge and the min size of the feature. It should be noted that the deviation can amount to the dimensional tolerance plus double the cylindricity tolerance.


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II

Fig 124 Fig 125

The toleranced surface shall (when checked in accordance with the adjacent measuring principle) be contained between two coaxial cylinders a radial distance 0,1 apart.

Measuring of cylindricity in a V-block with an indicating device placed in front of the V-block.

The V-block shall be longer than the measuring object.

The cylinder surface shall be measured in a radial section during one revolution c. The measuring shall be repeated in the required number of sections d. Half of the maximum difference between max and min readings on the entire cylinder surface shall be regarded as the cylindricity deviation.

The measuring shall be carried out in two V-blocks, 90 and 120 respectively, whereby also certain lobing is checked.

III

Fig 126


Aligned and measured in accordance with figure 125 but only in a 120 V-block.

Half of the maximum difference between max and min readings on the entire cylinder surface shall be regarded as the cylindricity deviation.



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IV

Fig 127 Fig 128


The cylinder surface shall be measured in a radial section while being rotated one revolution. c. The measuring shall be repeated in the required number of sections.d. Half of the maximum difference between max and min readings on the entire cylinder surface shall be regarded as the cylindricity deviation.


V

Fig 129 Fig 130


The straightness deviation of the generator is measured. It may be 0,3 max.

The measuring shall be repeated on the required number of generators.

The cylinder surface shall be measured in the required number of sections by the required number of two-point measurements.

The difference between max and min readings obtained on the entire cylinder surface may be 0,3 max.



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14.5 Profile tolerance of any line The tolerance zone is limited by two lines enveloping circles of diameter t, the centres of which are situated on a line having the true geometrical form. See figure 131.

See also section 14.10.4 Profile position.

The tolerance zone is bent and tubular and is limited by all spheres of diameter t, the centres of which are situated on a line having the true geometrical form. See figure 132. This tolerance zone is not included in SS-ISO 1101.

See also section 14.10.4 Profile position.

Fig 131 Fig 132


I

Fig 133 Fig 134

The profile shall be contained between two lines determined by circles of diameter 0,1, the centres of which are situated on a line having the true geometrical form.

Two points on the profile, as far apart as possible, shall be aligned to the same distance from the measuring plane.

The profile shall be measured at the required number of measuring points.

The readings obtained are recorded in a diagram where two equidistant lines are plotted in relation to the theo-retically exact profile.

Measuring with profile projector is also referred to this measuring principle.


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II

Fig 135

The profile shall (when checked in accordance with the adjacent measuring principle) be con-tained between two lines determined by circles of diameter 0,1, the centres of which are situated on a line having the true geometrical form.

The measuring object shall be aligned and measured in accordance with figure 134. The difference between max and min readings shall, when compared to theoretically exact profile, lie within

t tolerance2

, in this case 0,05.

The difference obtained is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the defi-nition of the tolerance (measuring principle I ).

III

Fig 136 Fig 137

The surface shall (when checked in accordance with the adjacent measuring principle) in each section parallel to the plane of projection be con-tained between two lines determined by circles of diameter 0,1, the centres of which are situated on a line having the true geometrical form.

The dimensions of the profile template correspond to the

GO side (theoretically exact profile +tolerance

2).

The profile template shall be placed on the surface. (The profile template constitutes tangent line to a section in the surface). The distance between profile template and surface shall be gauged by means of, e g, measuring wires and must not exceed the value specified in the tolerance frame. The check shall be repeated in the required number of sections. The largest distance obtained shall be regarded as the profile form deviation. The deviation is always larger than or equal to the devia-tion which would have been obtained if the check had been carried out in accordance with the definition of the tolerance (measuring principle I).


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I

Fig 138 Fig 139

The axis of the part shall be contained within a "bent pipe" of diameter 0,2, the axis of which is of the theoretically exact form + maximum material principle.


II

Fig 140 Fig 141

The axis of the part shall (when checked in accor-dance with the adjacent measuring principle) be contained within a "bent pipe of diameter 0,2, the axis of which is of the theoretically exact form + maximum material principle.

By means of the straightedge it shall be checked that no part of the measuring object is placed above the surface of the fixture.


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14.6 Profile tolerance of any surface The tolerance zone is limited by two surfaces enveloping spheres of diameter t, the centres of which are situated on a surface having the true geometrical form. See figure 142.

See also section 14.10.5 Surface position.

Fig 142


I

Fig 143 Fig 144 The toleranced surface shall be contained be-tween two surfaces determined by spheres of diameter 0,1, the centres of which are situated on a surface having the true geometrical form.

Points on the surface shall be aligned in such a way that the deviation from the form template becomes a minimum (superimposed surface). The surface shall be measured continuously or at the number of points required with the encircling form tem-plate as a basis. The largest difference between max and min readings constitutes the surface profile deviation.

II

Fig 145 The toleranced surface shall (when checked in accordance with the adjacent measuring principle) be contained between two surfaces determined by spheres of diameter 0,1, the centres of which are situated on a surface having the true geometrical form.

The same alignment as in figure 144, the only difference being that three points as far apart as possible on the surface shall be aligned to equal distance from the measuring plane. The difference obtained between the max and min readings shall, when compared to the theoretically exact

form, be within tolerance2

, in this case 0,05.

The difference obtained is always greater than or equal to the deviation which would have been obtained if the check had been carried out in accordance with the defi-nition of the tolerance (measuring principle I).


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NOT FOR NEW DESIGN

III

Fig 146 Fig 147

Interpretation, see measuring principle. Profile tolerance for a surface.

A form template shall be placed on the surface (the form template constitutes tangent surface).

The difference in dimensions between encircling form template and surface shall be measured. This can be done with air column measurement or, in special cases, by means of marking paint.

The difference in dimensions is always greater than or equal to the value which would have been obtained if measuring had been in accordance with the definition of the tolerance.

IV

Fig 148 Fig 149

The toleranced surface shall (when checked in accordance with the adjacent measuring principle) be contained between two surfaces determined by spheres of diameter 0,1, the centres of which are situated on a surface having the true geometrical form. NOTE: The principle can only be used for rotation symmetrical parts.

The dimensions of the template correspond to the GO

side (theoretically exact profile +tolerance

2)

The measuring object shall be centred to the axis of ro-tation for the profile template and placed at the required distance from it. The distance between profile template and measuring object shall be measured at the required number of points with, e.g., measuring wire. The largest difference in distance between measuring object and profile template shall be regarded as the sur-face form deviation. The deviation is always greater than or equal to the de-viation which would have been obtained if the check had been carried out in accordance with the definition of the tolerance (measuring principle I ).


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Orientation tolerances

14.7 Parallelism tolerance

14.7.1 Parallelism tolerance of a line with reference to a datum line The tolerance zone when projected in a plane is limited by two parallel straight lines a distance t apart and parallel to the datum line, if the tolerance is only specified in one direction. See figure 150.

The tolerance zone is limited by a cylinder of a diameter t parallel to the datum line if the tolerance value is preceded by the sign . See figure 151.

Fig 150 Fig 151

14.7.2 Parallelism tolerance of a line with reference to a datum plane The tolerance zone is limited by two parallel planes a distance t apart and parallel to the datum plane. See figure 152.

14.7.3 Parallelism tolerance of a surface with reference to a datum line The tolerance zone is limited by two parallel planes a distance t apart and parallel to the datum line. See figure 153.

If it from a functional point of view is possible to turn the whole thing around and indicate require-ments for the parallelism of the line with reference to the surface, this is to be preferred from a measuring point of view.

14.7.4 Parallelism tolerance of a surface with reference to a datum plane The tolerance zone is limited by two parallel planes a distance t apart and parallel to the datum plane. See figure 154.

Fig 152 Fig 153 Fig 154


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14.7.1 Parallelism tolerance of a line with reference to a datum line Indication and interpretation Measuring principle

I

Fig 155 Fig 156

The toleranced axis in the horizontal direction shall be contained between two straight lines 0,2 apart, which are parallel to A, aligned with B and located in the horizontal plane.

The toleranced axis in the vertical direction shall be contained between two straight lines 0,1 apart, which are parallel to A, aligned with B and located in the vertical plane.

By means of the mandrel A, the measuring object shall be placed on supports and turned to positions E and F respectively.

The parallelism requirement 0,1 shall be checked in position E and the parallelism requirement 0,2 shall be checked in position F.

The parallelism deviation is obtained from

1 2 1

2

M M LL

where M1 less M2 is the difference be-

tween max and min readings.

II

Fig 157 Fig 158

The generator shall (when checked in accordance with the adjacent measuring principle) be con-tained between two straight lines 0,1 apart, which are parallel to A - B, aligned with C and located in the vertical plane.

The measuring object shall be placed on two V-blocks and aligned with C.

Measuring shall be carried out on the generator.

The difference obtained between max and min readings E shall be regarded as the parallelism deviation.


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I

Fig 159 Fig 160

The toleranced axis shall be contained within a cylinder of diameter 0,1, the axis of which shall be parallel to A.

The parallelism is measured from 0 to 180 at the re-quired number of points.

The parallelism deviation is obtained from 1 2 12

M M LL

where M1 less M2 is the difference between max and min readings.

The measuring points may be reduced to 0 to 90 if the difference between max and min readings obtained for these points is maximum 0,7 x the tolerance.

14.7.2 Parallelism tolerance of a reference to a datum plane Indication and interpretation Measuring principle

I

Fig 161 Fig 162

The edge line (edge) shall be contained between two parallel planes 0,1 apart and parallel to A.

Measuring shall be carried out on the edge line.

The difference between max and min readings consti-tutes the parallelism deviation.


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14.7.3 Parallelism tolerance of a surface with reference to a datum line Indication and interpretation Measuring principle

I

Fig 163 Fig 164

The toleranced surface shall be contained be-tween two parallel planes 0,1 apart and parallel to A.

The measuring object shall be aligned in such a way that the smallest possible difference in dimensions is obtained against the measuring plane.




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14.7.4 Parallelism tolerance of a surface with reference to a datum plane Indication and interpretation Measuring principle

I

Fig 165 Fig 166

The toleranced surface shall be contained be-tween two parallel planes 0,1 apart and parallel to the datum.



II

Fig 167 Fig 168

The toleranced surface shall (when checked in accordance with the adjacent measuring principle) be contained between two parallel planes 0,1 apart and parallel to the datum.

The parallel shall be placed on the surface as tangent plane.

Measuring shall be carried out at points on the parallel corresponding to the extension of the toleranced surface.

The difference obtained between max and min readings shall be regarded as the parallelism deviation.

NOTE: The measuring principle does not check the form of the toleranced surface.


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14.8 Perpendicularity tolerance

14.8.1 Perpendicularity tolerance of a line with reference to a datum line The tolerance zone when projected in a plane is limited by two parallel straight lines a distance t apart and perpendicular to the datum line. See figure 169.

14.8.2 Perpendicularity tolerance of a line with reference to a datum plane The tolerance zone when projected in a plane is limited by two parallel straight lines a distance t apart and perpendicular to the datum plane if the tolerance is specified only in one direction. See figure 170.

The tolerance zone is limited by a cylinder of diameter t perpendicular to the datum plane if the tole-rance value is preceded by the sign . See figure 171.

Fig 169 Fig 170 Fig 171

14.8.3 Perpendicularity tolerance of a surface with reference to a datum line The tolerance zone is limited by two parallel planes a distance t apart and perpendicular to the datum line. See figure 172.

14.8.4 Perpendicularity tolerance of a surface with reference to a datum plane The tolerance zone is limited by two parallel planes a distance t apart and perpendicular to the datum plane See figure 173.

Fig 172 Fig 173


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14.8.1 Perpendicularity tolerance of a line with reference to a datum line Indication and interpretation Measuring principle

I

Fig 174 Fig 175

The axis of the hole shall be contained between two parallel lines 0,1 apart and perpendicular to A.

The measuring object shall be in a V-block on mandrel 1. Mandrel 2 is supported by an adjustable support. The guiding rule is fixed in a position perpendicular to the axis of mandrel 1. Two points of the generator of the mandrel (mandrel 2) shall be aligned to equal distance from the measuring plane. The perpendicularity is measured on one side of the mandrel, one measuring length being equal to the length of the hole. The difference between max and min readings consti-tutes the perpendicularity deviation.

I

Fig 176 Fig 177

The axis of the pin shall be contained between two parallel lines 0,1 apart and perpendicular to the axis of the horizontal hole (datum).

The smallest circumscribed cylinder (sleeve) shall be entered on the toleranced feature. The measuring object shall be placed on the measuring surface by means of a mandrel. Measuring shall be carried out at two points on the sleeve corresponding to the extension of the toleranced feature. The difference between max and min readings consti-tutes the perpendicularity deviation. As an alternative, the check can be carried out by meas-uring directly on the toleranced feature. In that case, the values shall be entered in a diagram and the inclination shall be evaluated Form deviations and differences in diameter shall then be taken into consideration and the result adjusted accordingly.



Issue 5 Page 54


II

Fig 178 Fig 179

The axis of the pin shall (when checked in accor-dance with the adjacent measuring principle) be contained between two parallel lines 0,1 apart and perpendicular to the axis of the horizontal hole (datum).

The measuring object shall be placed on the measuring plane by means of a mandrel.

Measuring shall be carried out on the two opposite gen-erators at the same level from the measuring plane.

Half the difference in measuring value between the dial

indicators, i.e. Ma Mb

2 at each point, indicates the

position of the axis in the section.

The largest difference between the different values for Ma Mb

2 shall be regarded as the perpendicularity

deviation.


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14.8.2 Perpendicularity tolerance of a line with reference to a datum plane Indication and interpretation Measuring principle

I

Fig 180 Fig 181

The axis of the pin shall be contained between two parallel lines 0,1 apart, perpendicular to A and aligned with B.

The smaller circumscribed cylinder (sleeve) shall be en-tered on the toleranced feature.

The measuring object shall be placed on surface A against the measuring plane and then guided with surface B against 90 measuring support.

Measuring shall be carried out at two points on the sleeve corresponding to the extension of the toleranced feature.

The difference between max and min readings consti-tutes the perpendicularity deviation.

As an alternative the check can be carried out by meas-uring directly on the toleranced feature. In that case, the values shall be entered in a diagram and the inclination shall be evaluated. Form deviations and differences in diameter shall then be taken into consideration and the result adjusted accordingly.


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II

Fig 182

The axis of the pin shall (when checked in accor-dance with the adjacent measuring principle) be contained between two parallel lines 0,1 apart, perpendicular to A and aligned with B.

The measuring object shall be aligned as shown in figure 181 but measuring shall be carried out directly on the toleranced pin.

Measured along the generator.

The difference between max and min readings shall be regarded as the perpendicularity deviation.

I

Fig 183 Fig 184

The axis of the pin shall be contained within a cylinder of diameter 0,1 + maximum material principle and perpendicular to A.



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I

Fig 185 Fig 186

The axis of the pin shall be contained within a cylinder of diameter 0,1 which is perpendicular to A

The smallest circumscribed cylinder (sleeve) shall be entered on the toleranced feature.

The measuring object is placed with its surface on a cir-cular feed table and the centre of the sleeve in measuring position b is placed at the centre of the axis of rotation.

Measuring takes place in position c where the part is rotated one revolution.

The difference between max and min readings must not exceed 0,2.

II

Fig 187 Fig 188

The axis of the pin shall (when checked in accor-dance with the adjacent measuring principle) be contained within a cylinder of diameter 0,1 which is perpendicular to A.

Measuring device: Apparatus for measuring variation in radius from fixed centre.

The cylinder surface shall be measured in a radial section while being rotated one revolution.c. The measuring shall be repeated in the required number of sections. d. The difference between max and min readings of the indicator must not exceed 0,2.


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14.8.3 Perpendicularity tolerance of a surface with reference to a datum line Indication and interpretation Measuring principle

I

Fig 189 Fig 190

The toleranced surface shall be contained be-tween two parallel planes 0,1 apart and perpen-dicular to A.

See also total run-out, figure 380.

The measuring object shall be clamped in the encircling guide cylinder.


The difference between max and min readings must not exceed 0,1.

NOT FOR NEW DESIGN

II

Fig 191 Fig 192

For interpretation, see measuring principle. Perpendicularity of a surface.

The part shall be fixed in a V-block.

The surface shall be measured in many directions.

The largest difference between max and min readings constitutes the perpendicularity deviation.


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14.8.4 Perpendicularity tolerance of a surface with reference to a datum plane Indication and interpretation Measuring principle

I

Fig 193 Fig 194

The toleranced surface shall be contained be-tween two parallel planes 0,1 apart perpendicular to A and aligned with B.

The measuring object shall be placed with surface A against the measuring plane and then aligned with sur-face B against a 90 measuring support.


The difference between max and min readings consti-tutes the perpendicularity deviation.

III

Fig 195 Fig 196

The toleranced surface shall (when checked in accordance with the adjacent measuring principle) be contained between two parallel planes 0,1 apart, perpendicular to A and aligned with B.

The measuring object shall be placed with surface A against the measuring plane and then guided with surface B against a 90 measuring support.

A parallel shall be placed on the toleranced surface as a tangent plane

Measuring shall be carried out on the parallel at points corresponding to the extension of the toleranced surface.

The difference between max and min readings shall be regarded as the perpendicularity deviation.

NOTE: The measuring principle does not check the form of the toleranced surface.


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I

Fig 197 Fig 198

The toleranced surface shall be contained be-tween two parallel planes 0,1 apart and perpen-dicular to A.

(The requirement may be indicated for rotation-symmetrical parts and other parts where no alignment against additional datum is required.)

The measuring object shall be placed with surface A against the measuring plane and aligned so that the smallest variance in dimensions is obtained against the auxiliary plane.


The difference