tolerancing and engineering standards
DESCRIPTION
TOLERANCING AND ENGINEERING STANDARDSTRANSCRIPT
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TOLERANCING AND ENGINEERING STANDARDS
Tolerancing is just like written languages. It has its own standards. There are to many standards like ANSI(Inch System), ISO (Metric System) etc. List of standards: ANSI B4.1, ANSI B4.2, ISO 286, ISO 1829, ISO 2768, EN 20286, JIS B 0401. In an assembly process the degree of "clearance" or "tightness" desired between mating parts is important. In a manufacture of a machine, quality is a primary consideration. Manufacturing precision taken into the product determines its quality, its cost and selling price. Parts of a machine are designed in order to make a function. The working parts have a definite relationship with each other: free rotation, free longitudinal movement, clamping action, and permanent fixed position. Precision is the degree of accuracy necessary to ensure the functioning of a part as intended. Tolerance is the allowable variation for any given size in order to achieve a proper function.
Tolerancing Definitions
NOMINAL SIZE : The size used for general description. Example; 7/8 inch Shaft, 25mm Shaft etc. BASIC SIZE : The size used when the nominal size is converted to the decimal and from which deviation are made to produce limit dimension. Example: .8750inch shaft which is the basic size for a 7/8 inch nominal shaft.25mm nominal size which can be basic size of 24.950mm. LIMIT DIMENSION : The Lower and Upper permitted sizes for a single feature dimension. 0.500-0.506 inch where 0.500 inch is the lower limit and 0.506 inch upper limit dimensions TOLERANCE :Tolerance is the allowable variation for any given size in order to achieve a proper function. Tolerance equals the difference between lower and upper limit dimensions. Example; for 0.500-0.506 inch the tolerance would be 0.006 inch.
BILATERAL TOLERANCE : It is a way to express tolerance by using both minus and plus variations from a given size. Example;
inch. The limit dimensions are 1.120-1.130 inch. The tolerance is 0.010 inch.
UNILATERAL TOLERANCE : It is a way to express tolerance by using only minus or plus variation from a given size. Example
inch. As you can see the first case uses a minus variation.
or
inch. The first case uses a minus and plus variation.
FIT : The general term of fit to describe the range of tightness designed into parts which assemble one into another. The fit can be explained under the three categories.
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A-CLEARANCE FIT : A type of fit in which one part fits easily into another with a resulting clearance gap. See the below example,
A clearance fit. The shaft is always smaller than the hole
Tolerance on shaft : 0.002
Tolerance on hole : 0.002
minimum clearance : 0.600 - 0.595 = 0.005 inch
maximum clearance : 0.602 - 0.593= 0.009 inch
The 0.005 clearance in for the tightest possible fit.
B-FORCE (INTERFERENCE) FIT : A type of fit in which one part must be forcibly fitted into another. See the below example
An Force (interference) fit. when the shaft is always larger in diameter than the hole parts must be assembled by
pressure or heat expansion.
Tolerance on shaft : 0.001
Tolerance on hole : 0.001
minimum clearance : 0.500 - 0.503= -0.003 in (the tightest fit 0.003 in interference)
maximum clearance : 0.501 - 0.502 = -0.001 in (the loosest fit 0.001 in interference)
Maximum clearance=Minimum interference
Minimum clearance=Maximum interference
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C-TRANSITION FIT : A type of fit in which loosest case provides a clearance fit and the tightest case gives an interference fit. See the example below,
A transition fit exist when the maximum clearance is positive and the minimum clearance is negative
Tolerance on shaft : 0.005
Tolerance on hole : 0.005
minimum clearance : 0.500 - 0.507 = -0.007 inch
The tightest fit is 0.007 in interference.
maximum clearance : 0.505 - 0.002 = 0.503 inch
The loosest fit is 0.003 in clearance
Transition fits are used only for locating a shaft relative to a hole,
where accuracy is important but either a clearance or interference is permitted.
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ALLOWANCE : An alternative expression for tightest possible fit, which is minimum clearance or maximum interference
Maximum allowance is 0.003.
BASIC-SHAFT SYSTEM : This is a system in which the basic size is included as one of the limit dimensions of the shaft. But it is not for the hole. As an example: for a basis size of 1.000 inch. The limit dimensions on the shaft could be 1.000 and 1.005 inch. The related hole could be 1.011 and 1.018 inch. BASIC-HOLE SYSTEM : This is a system in which the basic size appears as one of the limit dimensions of the hole. But it is not for the shaft. As an example for a basic size of 1.000 inch, the limit dimensions of the hole might be 1.000 and 1.007 inch. For the related shaft the limit dimensions could be 0.994 and 0.989 inch. MINIMUM MATERIAL CONDITION : In this condition a hole is at its largest limit dimension. A shaft is at its smallest limit dimension. This condition exists at maximum clearance or minimum interference. MAXIMUM MATERIAL CONDITION : In this condition a hole is at its smallest limit dimension. The shaft is at its largest limit dimension. This condition exists at minimum clearance or maximum interference. See example under the Force fit condition.
Hole And Shaft Basis Limits And Fits
Hole basis limits and fits with Shaft basis limits and fits have been given as an example in the chart below. The definitions for descriptions given in the chart explained as follows. The chart below gives simple understanding of Hole Basis Limits and Shaft Basis Limits. Some of the application and some of the selected Preferred Fits for Hole and Shaft Basis system have been given followed by Fits explanations.
More Clearance
(Close to Top of The Chart)
Clearance
Fits
Description
Hole
Basis
Shaft
Basis
Free Running H9/d9 D9/h9
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More Interference
(Close to Bottom of The
Chart)
Loose Running H11/c11 C11/h11
Easy Running H8/f8 F8/h8
Sliding H7/g6 G7/h6
Close Clearance H8/f7 F8/h7
Locational Clearance H7/h6 H6/h7
Transition
Fits
Location- slight
interference H7/k6 K7/h7
Location/Transition H7/n6 N7/h6
Interference
Fits
Location/Interference H7/p6 P7/h6
Medium Drive Fit H7/s6 S7/h6
Force Fit H7/u6 U7/h6
Free Running; This type of tolerance can be usable where any special requirements for accuracy in not essential, but good for wide temperature variation, heavy journal pressures and high running speeds. Some of the applications: Multiple fits of shafts of production and piston machines, parts rotating very rarely or only swinging.. Some of the selected Preferred fits: H9/d9, D9/h9, H9/C9, H9/d10, D9/h8, H8/d9, H8/d8, D10/h9,
Loose Running; Fits For wide commercial tolerances/clearances or allowances with parts on external members. Some of the applications: Fits of parts exposed to corrosive effects, pivots, latches, contamination with dust and thermal or mechanical deformations. Some of the selected Preferred fits: H11/c11, H11/a11, C11/h11, H11/c9, D11/h11, H11/d11, A11/h11,
Easy Running; This is tuning fits with smaller clearances with general requirements for fit accuracy. Some of the applications: Main fits of machine tools. General fits of shafts, regulator bearings, machine tool spindles, sliding rods. Some of the selected Preferred fits: H8/f8, H9/f8, F8/h6, F8/h7, H8/f7, H7/f7,
Sliding/Running Fit; This fit does not provide freely running. This running/sliding tolerance fits with very small clearances for accurate guiding of shafts. This kind of tolerance helps the parts to move and turn freely and locate accurately. Some of the applications: sliding gears and clutch disks, parts of machine tools, pistons of hydraulic machines, rods sliding in bearings, grinding machine spindles, crankshaft journals. Some of the selected Preferred fits: H7/g6, H8/g7, G7/h6,
Close Clearance ( Spigots and Locations);This fit is for accurate location at moderate speeds and journal pressures, and running on accurate machine parts. Running fits with smaller clearances with general requirements for fit accuracy. Some of the applications: General fits of shafts, machine tool spindles, main fits of machine tools, regulator bearings, sliding rods. Some of the selected Preferred fits: H8/f7, F8/h7, F8/h6, H9/f8, H8/f8, H7/f7,
Locational Clearance; For locating stationary parts, it provides snug fit. It provides freely assemble and disassemble. This fit helps for precise guiding and centering of parts and mounting by sliding on without use of any great force, after lubrication the parts can be turned and slid by hand. Some of the applications: Roller guides. precise guiding of machines and preparations, exchangeable
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wheels. Some of the selected Preferred fits: H7/h6, H8/h7, H8/h9, H8/h8,
Location- slight interference; This type of fit compromise between interference and clearance for accurate location. With this fit, the parts can be assemble or disassemble without great force using a rubber mallet. Some of the applications: Clutches, demountable fits of hubs of gears and pulleys, manual wheels, brake disks. Some of the selected Preferred fits: H7/k6, H8/k7, K7/h6, K8/h7,
Location/Transition; This fit for accurate location where greater interference permissible. It is fixed fits with small interferences or negligible clearances. Mounting of fits using pressing and light force. Some of the applications: Armatures of electric motors on shafts, gear rims, fixed plugs, driven bushings, flushed bolts. Some of the selected Preferred fits: H7/n6, H8/n7, H8/p7, H7/m6, H8/m7, M8/h6, N7/h6, N8/h7,
Location/Interference; This type of fit where the assembled parts requiring rigidity and great alignment with prime accuracy of location. Press fit which can be separated, pressed fits with guaranteed interference. Assembly of the parts can be carried out using cold pressing. Some of the applications: Bearing bushings, Hubs of clutch disks. Some of the selected Preferred fits: H7/p6, H7/r6, H8/r7, P7/h6, R7/h6,
Medium Drive Fit This fit for shrink fit on light section or ordinary steel parts. Pressed fits with medium interference, assembly of parts using hot pressing, assembly using cold pressing only with use of large forces. the tightest tolerance usable for cast iron. Some of the applications: Permanent coupling of gears with shafts, bearing bushings. Some of the selected Preferred fits: H7/s6, H8/s7, H7/t6, H8/t7, S7/h6, T7/h6,
Force Fit; This fit suitable for parts which can be highly stressed. Pressed fits with big interferences, assembly using pressing and great forces under different temperatures of the parts. This fit for shrink fits where the heavy pressing forces required are impractical. Some of the applications: Permanent couplings of gears with shafts, flanges. Some of the selected Preferred fits: H7/u6, H8/u7, H8/u8, H8/x8, U7/h6, U8/h7,
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ISO Tolerance Systems For Limits And Fits
This standard can be described as ISO 286:1988.This standard is being described in USA as ANSI (ANSI B4.2-1978). American National Standard (ANSI B4.2-1978) describes ISO standard of metric fits and limits for mating machine parts as approved for general engineering usage. This Standard is used as an international standard for linear dimension tolerances. This ISO system is identical with the European standard (EN 20286:1993) and defines an internationally recognized system of tolerances, deviations and fits. This system has been accepted in most industrially developed countries in identical or by modifying wording system as a their national standard like Japan, British, USA (JIS B 0401, DIN ISO 286, BS EN 20286, CSN EN 20286, etc.). General terms of shaft and hole can also be taken to refer to the space contained by two parallel faces of any part, e.g. fits of keys in grooves. The most important term relating to fits and limits are showmen in the figure below;
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Deviations from the exact dimensions are unavoidable due to the nature of manufacturing processes.
Deviation: Difference between the size and the corresponding basic size. The basic size is assigned as limits of deviation. it is same for both parts of their fits.
Lower Deviation: Difference between the min limit of part's size and corresponding basic size. It is designated "EI" for Hole, "ei" for shaft
Upper Deviation: Difference between the max limit of part's size and the corresponding basic size. It is designated "ES" for hole," es" for shaft
Fundamental Deviation: One of the deviations closest to the basic size.
For easy understanding of the "es", "ei", "ES", and "EI" and identification of their negative and positive values, the letter may be interpreted as follow;
es: Error from zero line (Basic Size) to superior size of shaft.
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ei: Error from zero line (Basic Size) to inferior size of shaft.
ES: Error from zero line (Basic Size) to superior size of hole.
EI: Error from zero line (Basic Size) to inferior size of hole.
Tolerance Zone: A zone representing the tolerance and its position in relating to the basis size. The tolerance zone is also defined as a spherical zone limited by the upper and lower limit dimensions of the part.
Tolerance: The algebraic difference between the max and min limits on the part.
International Tolerance Grade (IT)
IT grade is a group of tolerances. Each of the tolerances of this system is marked "IT" with attached grade of accuracy (IT01, IT0, IT1 ... IT18).IT Grades reference ISO 286. The magnitude of the tolerance zone is the variation in part size. IT groups of tolerances such that tolerances for a particular IT number have the same relative level of accuracy but vary depending on the basic size. A smaller grate of IT number provides a smaller tolerance zone. The fundamental IT deviation for hole basis is designated by "H", the shaft designated by "h".
Tolerance Symboles:The tolerance symbol is established by combining the IT grade number and position letter for tolerance. Capital letter like "H" for hole, and lower case letter like "h" for shaft.
Showing Internal part with IT symbol:
Showing External Part with IT symbol:
Application Field of International Tolerances of ISO 286 system:
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APPLICATIONS IT Grade Range
Measuring Instruments and Production of Gauges IT01, IT0, IT1, IT2, IT3, IT4, IT5, IT6
General Engineering/Industry and Precision Fit IT 5, IT6, IT7, IT8, IT9, IT10, IT11, IT12
Semi Finished Product IT11, IT14, IT15, IT16
Structural Engineering IT16, IT17, IT18
Fundamental Deviations Letter For Hole and Shaft Basis.
The Value for the Hole from "A" to "H" are positive (+), for the Shaft from "a" to "h" negative (-). The Value of the Hole from "J" to "K" either positive (+) or negative (-), for Shaft form "j" to "k" either positive (+) or negative (-).
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Applications with ISO 286/ANSI B4.2-1978 International Tolerance Grade.
For best fit selection for a specific applications many factors can be effective. Such as speed, temperatures, length engagement, materials, lubrications, humidity, bearing load and etc. To satisfy extreme conditions the best preferred fit must be considered. The tolerances indicated by the International Tolerance (IT) Grades are general guide to machining process given in ISO 286/ANSI B4.2-1978 showmen in the below table.
APPLICATIONS and PROCESS IT Grade Range
LAPPING AND HONING IT1, IT2, IT3, IT4, IT5,
CYLINDRICAL TURNING AND DIAMOND TURNING IT4, IT5, IT6, IT7
PLANE/ SURFACE GRINDING IT5, IT6, IT7, IT8, IT9
BROACHING AND REAMING IT5, IT6, IT7, IT8, IT9
BORING AND TURNING
IT6, IT7, IT8,
IT9, IT10, IT11, IT12
SAWING IT9, IT10, IT11
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POWDER METAL-SINTERED IT7, IT8, IT9,IT10
MILLING IT9,IT10,IT11, IT12, IT13
PLANING, SHAPING, COLD ROLLING AND
DRAWING IT10, IT11, IT12, IT13,IT14,
COLD ROLLING AND DRAWING IT 4, IT5, IT6,IT7
DRIILING IT11, IT12,IT13, IT14
DIE CASTING IT12,;IT13,IT14, IT15
PUNCHING AND FORGING IT13,IT14, IT15,IT16
HOT ROLLING, FALME CUTTING AND SAND
CASTING IT1 4,IT15, IT16
ISO 286 TOLERANCE BAND IT01 To IT7
Tolerance Band Given Below (IT01 To IT7) In Micrometer=(10-3)
mm
Example: IT1 For Nominal Size 0-3mm; 0.8m=0.8x(10-3
)=0.0008mm
NOMINAL( BASIC) SIZES (mm) INTERNATIONAL TOLERANCE GRADES
OVER UP TO INCL. IT01 IT0 IT1 IT2 IT3 IT4 IT5 IT6 IT7
0 3 0.3 0.5 0.8 1.2 2 3 4 6 10
3 6 0.4 0.6 1 1.5 2.5 4 5 8 12
6 10 0.4 0.6 1 1.5 2.5 4 6 9 15
10 18 0.5 0.8 1.2 2 3 5 8 11 18
18 30 0.6 1 1.6 2.6 4 6 9 13 21
30 50 0.8 1 1.6 2.6 4 7 11 16 25
50 80 0.8 1.2 2 3 5 8 13 19 30
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80 120 1 1.5 2.5 4 6 10 16 22 35
120 180 1.2 2 3,5 5 8 12 18 25 40
180 250 2 3 4.5 7 10 14 20 29 46
250 315 2.5 4 6 8 12 16 23 32 62
315 400 3 5 7 9 13 18 25 36 57
400 500 4 6 8 10 16 20 27 40 63
500 630 4.5 6 9 11 16 22 30 44 70
630 800 5 7 10 12 18 25 35 50 80
800 1000 5.5 8 11 15 21 29 40 56 90
1000 1250 6.5 9 13 18 24 34 46 66 105
1250 1600 8 11 16 21 29 40 54 78 126
1600 2000 9 13 18 26 35 48 65 92 160
2000 2500 11 16 22 30 41 67 77 110 175
2500 3150 13 18 26 36 60 69 93 135 210
Equation Chart to Calculate Fundamental Deviation of Shaft Size Up to 500mm (Geometric Mean Dia "mm")
FORMULAE FOR FUNDAMENTAL DEVIATION FOR SHAFTS SIZES UP TO 500 mm
UPPER DEVIATION (es) LOWER DEVIATION (ei)
Shaft Designation In Microns (for D in mm) Shaft Designation In microns (for D in mm)
a
= -(265 + 1.32D) for D 120
;and
= 3.52D for D > 120
j5 to j8 No formula
js ITx1/2
k4 to k7 =+ 0.6x 3 D
b
= (140 + 0.852D); for D 160
k for Grade 3 and 4 =0
m = + (T7-IT6)
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c
= 52D0.2 for D 40
= -(95 + 0.82) for D> 40
n = + 5D0.34
P = + IT7 + 0 to 5
cd G.M. of values for c and d
r
= geometric mean of
values for p and s
d = 16D0.44
s
= IT8 + 1 to 4; for D 50
= + 7T7 to + 0.4D; for D > 50
e = -11D0.41
ef G.M. of values for e and f
f = -5.5D0.41 t = + IT7 + 0.63D
fg G.M. of values for f and g u = + IT7 + D
g = -2.5D0.34 V = + IT1 + 1.2525D
h = 0
X = + IT7 + 1.62D
y = + IT7 + 2D
z = + IT7 + 2.52D
za = IT8 + 3 + 3.152D
zb = + IT9 + 4D
zc = + IT10 + 4D
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ALL DEVIATIONS EXCEPT
THOSE GIVEN BELOW
GENERAL RULE:
Hole limits are identical with the shaft limits of the same
symbole (Letter and Grade)but disposed on the other side of the
zero line.EI=-es (EI is equal upper deviation of shaft of the same
letter symbol but of opposite sign.)
N
IT9 and Closer
Grades ES=0
For Size Above
3mm
J,K.M,
and N
Up to Grade
IT8 Inclusive
SPECIALS RULES:
ES= Lower deviation ei of the shaft of the same letter symbol
but one grade finer and of opposite sign increased by the
difference between the tolerances of the two grades in;
ei+ITx=ES+ITn and ei-ITn= ES-ITx (x=n-1)
For Size Above
3mm P to ZC
Up to Grades
7 inclusive
Formulae For Fundamental Deviations of Shafts up to size 500-3150mm
SHAFT HOLES
FORMULAE
FOR
DEVIATION
IN MICRON
SHAFT
DESIGNATION
FUNDAMENTAL
DEVIATION SIGN
HOLE
DESIGNATION
FUNDAMENTAL
DEVIATION SIGN
For "D" in
mm
d es - D EI + 16D0.44
e es - E EI + 11D0.41
f es - F EI + 5.5D0.41
g es - G EI + 2.5D0.34
h es
No
Sign H EI
No
Sign 0
js ei - JS ES + 0.5ITn
k ei + K ES - 0
m ei + M ES - 0.024D+12.6
n ei + N ES - 0.04+21
p ei + P ES - 0.072D+37.8
r ei + R ES -
Geometric
mean of the
values "p"
and "s" or
"P" and "S"
s ei + S ES - IT7+0.4D
t ei + T ES - IT7+0.63D
u ei + U ES - IT7+D
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ISO 286 Tolerance Band "IT8" To "IT16"
Tolerance Band Given Below (IT8 To IT16) In Micrometer=(10
-3)mm
NOMINAL( BASIC) SIZES (mm) INTERNATIONAL TOLERANCE GRADES
OVER UP TO INCL. IT8 IT9 IT10 IT11 IT12 IT13 IT14 IT15 IT16
0 3 14 25 40 60 100 140 250 400 600 3 6 18 30 48 75 120 180 300 480 760 6 10 27 36 68 90 60 220 360 580 900 10 18 27 43 70 110 180 270 430 700 1100 18 30 33 52 84 130 210 330 520 840 1300 30 50 39 62 100 160 260 390 620 1000 1600 50 80 46 74 120 190 300 460 740 1200 1900 80 120 64 87 140 220 350 540 870 1400 2200 120 180 60 100 160 250 400 630 1000 1600 2500 180 250 72 115 185 290 460 720 1150 1850 2900 250 315 81 130 210 320 620 810 1300 2100 3200 315 400 89 140 230 360 570 890 1400 2300 3600 400 500 97 155 250 400 630 970 1500 2500 4000 500 630 110 175 280 440 700 1100 1750 2800 4400 630 800 125 200 320 500 800 1250 2000 3200 6000 800 1000 140 230 360 560 900 1400 2300 3600 5600 1000 1250 165 260 420 660 1060 1650 2600 4200 6600 1250 1600 195 310 500 780 1260 1950 3100 5000 7800 1600 2000 230 370 600 920 1500 2300 3700 6000 920 2000 2500 280 440 700 1100 1750 2800 4400 7000 11000 2500 3150 330 540 860 1360 2100 3300 5400 8000 1350
Calculation of International Tolerance Grades:
As mentioned before IT Grade have 18 standard tolerance. These IT Grades have their own numerical values for each dimater step given in the tables above. IT Grades IT01 to IT5 are the most accurate and used essetially for gauge. IT Grades IT6 to IT 16 are less accurate and are used for nonmating dimensions. International Grade can be calculated as given below;
T:International Tolerance grade in (m)
D:Geometric mean dimension in millimeters (mm)
ITG:IT Grade (a positive integer)
Also T:International Tolerance can be showmen as;
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"i": is standard tolerance unit/factor."i" for IT5 to IT 16 values can be calculated with the formula below;
Unit tolerance in (m). To calculate D;
where, D (mm) is the geometric mean of the lower and upper diameters of a particular diameter step within which the chosen the diameter D lies. Standard Tolerance Unit/Factor the formula has parabolic relationship with the size of the products. As the size increases, the tolerance within which a part can be manufactured also increases.
The Standards Tolerance values corresponding to IT grades IT01, IT0, IT1, see the chart below
INTERNATIONAL TOLERANCE GRADES
Values In Microns IT01 IT0 IT1
Values For D In mm 0.3+0.008D 0.5+0.012D 0.8+0.020D
The Standards Tolerance values corresponding to IT grades IT5 to IT16, see the chart below
INTERNATIONAL TOLERANCE GRADES
Values In Microns IT5 IT6 IT7 IT8 IT9 IT10 IT11 IT12 IT13 IT14 IT15 IT16
Values For D In mm 7i 10i 16i 25i 40i 64i 100i 160i 250i 400i 640i 1000i
EXAMPLE:
Lets chose the diameter of the shaft 60mm, and Tolerance grade H8f7; Calculation for Fundamental deviation, Tolerances and Limit of size for Hole and, Shaft. Calculation of the Standard tolerance Unit;
The size range for 60mm Diameter would be 50-80mm from the ISO 286 table
D= 50 +80 mm=63.25mm
i=10-3 50 +60 +0.01x63.25=1.865micron or i=0.001865mm For Shaft of f7 "i" value standard unit from the table; Tolerance=16i=16x1.865=0.030mm For Hole of H8 "i" value standard unit from the table; Tolerance=25i=25x0.001865=0.046mm
Since design based on Hole basis, the fundamental deviation of hole is zero. Fundamental deviation for Shaft;
-
=-5.5xD0.41
=-5.5x63.250.41
=-30.114 microns=0.030mm
Shaft; Higher Limit=Basic size-Fundamental Deviation=60-0.030=59.97mm Lower Limit=Higher Limit-Tolerance=59.97-0.03=59.94mm Hole; Lower Limit=Basic Size=60mm Higher Limit=Lower Limit+Tolerance=60+0.046=60.046mm
Calculation of Upper (es) and Lower (ei) Deviation For Shaft:
The deviations and fundamental tolerances provided by the ISO System. The limits of tolerance for holes or shafts are designated by the appropriate letter indicating the fundamental deviation. And Tolerance grade is dominated by followed by a suffix number. For example, if the hole deviation "H" and tolerance grade IT7,; designation would be H7, if Shaft deviation "k" and tolerance grade IT6; designation would be k6.If the basic size 50mm, tolerance designation would be 50H7 and 50k6.
The Upper and Lower deviations for Shaft are donated by "es" and "ei". The Upper and Lower deviations for Hole are donated by "ES" and "EI". The Fundamental Deviations can be calculated with the help of some formulas given below.
Calculation Fundamental Upper and Lower Deviation Of Shaft:
es=ei+IT, ei=es-IT
Calculation Fundamental Upper and Lower Deviation Of Hole:
ES=EI+IT, EI=ES-IT
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Table Below: Fundamental Upper Deviation For Shaft "a" to "js" (0 mm To 500 mm)
Over
Up to
Incl.
FUNDAMENTAL UPPER DEVIATION (es ) IT01 to IT16
a b c cd d e ef f fg g h js
0 3 -270 -140 -60 -34 -20 -14 -10 -6 -4 -2 0 ITn/2
3 6 -270 -140 -70 -46 -30 -20 -14 -10 -6 -4 0 ITn/2
6 10 -280 -150 -80 -56 -40 -25 -18 -13 -8 -5 0 ITn/2
10 14 -290 -150 -95 -50 -32 -16 -6 0 ITn/2
14 18 -290 -150 -95 -50 -32 -16 -6 0 ITn/2
18 24 -300 -160 -110 -65 -40 -20 -7 0 ITn/2
24 30 -300 -160 -110 -65 -40 -20 -7 0 ITn/2
30 40 -310 -170 -120 -80 -50 -25 -9 0 ITn/2
40 50 -320 -180 -130 -80 -50 -25 -9 0 ITn/2
50 65 -340 -190 -140 -100 -60 -30 -10 0 ITn/2
65 80 -360 -200 -150 -100 -60 -30 -10 0 ITn/2
80 100 -380 -220 -170 -120 -72 -36 -12 0 ITn/2
100 120 -410 -240 -180 -120 -72 -36 -12 0 ITn/2
120 140 -460 -260 -200 -145 -85 -43 -14 0 ITn/2
140 160 -520 -280 -210 -145 -85 -43 -14 0 ITn/2
160 180 -580 -310 -230 -145 -85 -43 -14 0 ITn/2
180 200 -660 -340 -240 -170 -100 -50 -15 0 ITn/2
200 225 -740 -380 -260 -170 -100 -50 -15 0 ITn/2
225 250 -820 -420 -280 -170 -100 -50 -15 0 ITn/2
250 280 -920 -480 -300 -190 -110 -56 -17 0 ITn/2
280 315 -1050 -540 -330 -190 -110 -56 -17 0 ITn/2
315 355 -1200 -600 -360 -210 -125 -62 -18 0 ITn/2
355 400 -1350 -680 -400 -210 -125 -62 -18 0 ITn/2
400 450 -1500 -760 -440 -230 -135 -68 -20 0 ITn/2
450 500 -1650 -840 -480 -230 -135 -68 -20 0 ITn/2
Table Below: Fundamental Lower Deviation For Shaft "j" to "zc" (0 mm To 500 mm). Fundamental
Deviation IT01 to IT16 for "m" to "zc".
-
Over
Up to
Incl.
FUNDAMENTAL LOWER DEVIATION (ei)
j5/j6 j7 k4-k7 (incl.) other k m n p r s t u v x y z za zb zc
0 3 -2 -4 0 0 2 4 6 10 14 18 20 26 32 40 60
3 6 -2 -4 1 0 4 8 12 15 19 23 28 35 42 50 80
6 10 -2 -5 1 0 6 10 15 19 23 28 34 42 52 67 97
10 14 -3 -6 1 0 7 12 18 23 28 33 40 50 64 90 130
14 18 -3 -6 1 0 7 12 18 23 28 33 39 45 60 77 108 150
18 24 -3 -8 2 0 8 15 22 28 35 41 47 54 63 73 98 136 188
24 30 -3 -8 2 0 8 15 22 28 35 41 48 55 64 75 88 118 160 218
30 40 -4 -10 2 0 9 17 26 34 43 48 60 68 80 94 112 148 200 274
40 50 -4 -10 2 0 9 17 26 34 43 54 70 81 97 114 136 180 242 325
50 65 -5 -12 2 0 11 20 32 41 53 66 87 102 122 144 172 226 300 405
65 80 -7 -12 2 0 11 20 32 43 59 75 102 120 146 174 210 274 360 480
80 100 -9 -15 3 0 13 23 37 51 71 91 124 146 178 214 258 335 445 585
100 120 -9 -15 3 0 13 23 37 54 79 104 144 172 210 254 310 400 525 690
120 140 -11 -18 3 0 15 27 43 63 92 122 170 202 248 300 365 470 620 800
140 160 -11 -18 3 0 15 27 43 65 100 134 190 228 280 340 415 535 700 900
160 180 -11 -18 3 0 15 27 43 68 108 146 210 252 310 380 465 600 780 1000
180 200 -13 -21 4 0 17 31 50 77 122 166 236 284 350 425 520 670 880 1150
200 225 -13 -21 4 0 17 31 50 80 130 180 258 310 385 470 575 740 960 1250
225 250 -13 -21 4 0 17 31 50 84 140 196 284 340 425 520 640 820 1050 1350
250 280 -16 -26 4 0 20 34 56 94 158 218 315 385 475 580 710 920 1200 1550
280 315 -16 -26 4 0 20 34 56 98 170 240 350 425 525 650 790 1000 1300 1700
315 355 -18 -28 4 0 21 37 62 108 190 268 390 475 590 730 900 1150 1500 1900
355 400 -18 -28 4 0 21 37 62 114 208 294 435 530 660 820 1000 1300 1650 2100
400 450 -20 -32 5 0 23 40 68 126 232 330 490 595 740 920 1100 1450 1850 2400
450 500 -20 -32 5 0 23 40 68 132 252 360 540 660 820 1000 1250 1600 2100 2600
Table Below: Fundamental Upper Deviation For Shaft "d" to js; Lower Deviation For Shaft "k" to "u" (500
mm To 3150 mm)
-
Over
Up to
Incl.
FUNDAMENTAL UPPER DEVIATION (es) FUNDAMENTAL LOWER DEVIATION (ei)
d e ef f fg g h js k m n p r s t u
500 560 -260 -145 -76 -22 0 ITn/2 0 26 44 78 150 280 400 600
560 630 -260 -145 -76 -22 0 ITn/2 0 26 44 78 155 310 450 660
630 710 -290 -160 -80 -24 0 ITn/2 0 30 50 88 175 340 500 740
710 800 -290 -160 -80 -24 0 ITn/2 0 30 50 88 185 380 560 840
800 900 -320 -170 -86 -26 0 ITn/2 0 34 56 100 210 430 620 940
900 1000 -320 -170 -86 -26 0 ITn/2 0 34 56 100 220 470 680 1050
1000 1120 -350 -195 -98 -28 0 ITn/2 0 40 66 120 250 520 780 1150
1120 1250 -350 -195 -98 -28 0 ITn/2 0 40 66 120 260 580 840 1300
1250 1400 -390 -220 -110 -30 0 ITn/2 0 48 78 140 300 640 960 1450
1400 1600 -390 -220 -110 -30 0 ITn/2 0 48 78 140 330 720 1050 1600
1600 1800 -430 -240 -120 -32 0 ITn/2 0 58 92 170 370 820 1200 1850
1800 2000 -430 -240 -120 -32 0 ITn/2 0 58 92 170 400 920 1350 2000
2000 2240 -480 -260 -130 -34 0 ITn/2 0 68 110 195 440 1000 1500 2300
2240 2500 -480 -260 -130 -34 0 ITn/2 0 68 110 195 460 1100 1650 2500
2500 2800 -520 -290 -145 -38 0 ITn/2 0 76 135 240 550 1250 1900 2900
2800 3150 -520 -290 -145 -38 0 ITn/2 0 76 135 240 580 1400 2100 3200
Calculation of Upper (Es) and Lower (Ei) Deviation For Holes:
Table Below: Fundamental Deviation For IT01 To IT16. Fundamental Deviations "A" To "JS"; ITn's 6,7, and 8 For . Fundamental Deviations "J", ITn's 7,8, and >8 For "K"only applies.
-
Over
Up to
Incl.
FUNDAMENTAL LOWER DEVIATION (El) IT01 to IT16 FUNDAMENTAL UPPER DEVIATION (Es)
A B C CD D E EF F FG G H JS J6 J7 J8 K7 K8 >K8
0 3 270 140 60 34 20 14 10 6 4 2 0 IT/2 2 4 6 0 0 0
3 6 270 140 70 46 30 20 14 10 6 4 0 IT/2 5 6 10 3 5 0
6 10 280 150 80 56 40 25 18 13 8 5 0 IT/2 5 8 12 5 6 0
10 14 290 150 95 0 50 32 0 16 0 6 0 IT/2 6 10 15 6 8 0
14 18 290 150 95 0 50 32 0 16 0 6 0 IT/2 6 10 15 6 8 0
18 24 300 160 110 0 65 40 0 20 0 7 0 IT/2 8 12 20 6 10 0
24 30 300 160 110 0 65 40 0 20 0 7 0 IT/2 8 12 20 6 10 0
30 40 310 170 120 0 80 50 0 25 0 9 0 IT/2 10 14 24 7 12 0
40 50 320 180 130 0 80 50 0 25 0 9 0 IT/2 10 14 24 7 12 0
50 65 340 190 140 0 100 60 0 30 0 10 0 IT/2 13 18 28 9 14 0
65 80 360 200 150 0 100 60 0 30 0 10 0 IT/2 13 18 28 9 14 0
80 100 380 220 170 0 120 72 0 36 0 12 0 IT/2 16 22 34 10 16 0
100 120 410 240 180 0 120 72 0 36 0 12 0 IT/2 16 22 34 10 16 0
120 140 460 260 200 0 145 85 0 43 0 14 0 IT/2 18 26 41 12 20 0
140 160 520 280 210 0 145 85 0 43 0 14 0 IT/2 18 26 41 12 20 0
160 180 580 310 230 0 145 85 0 43 0 14 0 IT/2 18 26 41 12 20 0
180 200 660 340 240 0 170 100 0 50 0 15 0 IT/2 22 30 47 13 22 0
200 225 740 380 260 0 170 100 0 50 0 15 0 IT/2 22 30 47 13 22 0
225 250 820 420 280 0 170 100 0 50 0 15 0 IT/2 22 30 47 13 22 0
250 280 920 480 300 0 190 110 0 56 0 17 0 IT/2 25 36 55 16 25 0
280 315 1050 540 330 0 190 110 0 56 0 17 0 IT/2 25 36 55 16 25 0
315 355 1200 600 360 0 210 125 0 62 0 18 0 IT/2 29 39 60 17 28 0
355 400 1350 680 400 0 210 125 0 62 0 18 0 IT/2 29 39 60 17 28 0
400 450 1500 760 440 0 230 135 0 68 0 20 0 IT/2 33 43 66 18 29 0
450 500 1650 840 480 0 230 135 0 68 0 20 0 IT/2 33 43 66 18 29 0
Table Below: Fundamental Deviations For "M" and "N" ; ITn's 7,8, and >8 . Fundamental Deviations "P" To "ZC" ITn's> 7 only applies.
Over
Up to
Incl.
FUNDAMENTAL DEVIATION (Es )
M7 M8 >M8 N7 N8 >N8 P R S T U V X Y Z ZA ZB ZC
0 3 -2 -2 -2 -5 -4 -4 -6 -10 -14 0 -18 0 -20 0 -26 -32 -40 -60
3 6 0 2 -4 -4 -2 0 -12 -15 -19 0 -23 0 -28 0 -35 -42 -50 -80
6 10 0 1 -6 -4 -3 0 -15 -19 -23 0 -28 0 -34 0 -42 -52 -67 -97
10 14 0 2 -7 -5 -3 0 -18 -23 -28 0 -33 0 -40 0 -50 -64 -90 -130
14 18 1 5 -7 -5 -3 0 -18 -23 -28 0 -33 -39 -45 0 -60 -77 -108 -150
18 24 0 4 -8 -7 -3 0 -22 -28 -35 0 -41 -47 -54 -63 -73 -98 -136 -188
24 30 1 6 -8 -7 -3 0 -22 -28 -35 -41 -48 -55 -64 -75 -88 -118 -160 -218
30 40 0 5 -9 -8 -3 0 -26 -34 -43 -48 -60 -68 -80 -94 -112 -148 -200 -274
40 50 2 7 -9 -8 -3 0 -26 -34 -43 -54 -70 -81 -97 -114 -136 -180 -242 -325
50 65 0 5 -11 -9 -4 0 -32 -41 -53 -66 -87 -102 -122 -144 -172 -226 -300 -405
65 80 2 8 -11 -9 -4 0 -32 -43 -59 -75 -102 -120 -146 -174 -210 -274 -360 -490
80 100 0 6 -13 -10 -4 0 -37 -51 -71 -91 -124 -146 -178 -214 -258 -335 -445 -585
100 120 2 10 -13 -10 -4 0 -37 -54 -79 -104 -144 -172 -210 -254 -310 -400 -525 -690
120 140 0 8 -15 -12 -4 0 -43 -63 -92 -122 -170 -202 -248 -300 -365 -470 -620 -800
140 160 0 8 -15 -12 -4 0 -43 -65 -100 -134 -190 -228 -280 -340 -415 -535 -700 -900
160 180 2 11 -15 -12 -4 0 -43 -68 -108 -146 -210 -252 -310 -380 -465 -600 -780 -1000
180 200 0 9 -17 -14 -5 0 -50 -77 -122 -166 -236 -284 -340 -425 -520 -670 -880 -1150
200 225 0 9 -17 -14 -5 0 -50 -80 -130 -180 -258 -310 -385 -470 -575 -740 -960 -1250
225 250 3 12 -17 -14 -5 0 -50 -84 -140 -196 -284 -340 -425 -520 -640 -820 -1050 -1350
250 280 0 9 -20 -14 -5 0 -56 -94 -158 -218 -315 -385 -475 -580 -710 -920 -1200 -1550
280 315 1 12 -20 -14 -5 0 -56 -98 -170 -240 -350 -425 -525 -650 -790 -1000 -1300 -1700
-
315 355 0 11 -21 -16 -5 0 -62 -108 -190 -268 -390 -475 -590 -730 -900 -1150 -1500 -1900
355 400 2 13 -21 -16 -5 0 -62 -114 -208 -294 -435 -530 -660 -820 -1000 -1300 -1650 -2100
400 450 48 59 -23 -17 -6 0 -68 -126 -232 -330 -490 -595 -740 -920 -1100 -1450 -1850 -2400
450 500 25 25 -23 -17 -6 0 -68 -132 -252 -360 -540 -660 -820 -1000 -1250 -1600 -2100 -2600
Table Below: Fundamental Deviations "P" to "Z" For IT6 and IT7
Over
Up to
Incl.
FUNDAMENTAL DEVIATION (Es )
P6 P7 R6 R7 S6 S7 T6 T7 U6 U7 V6 V7 X6 X7 Y6 Y7 Z6 Z7
0 3 -6 -6 -10 -10 -14 -14 0 0 -18 -18 0 0 -20 -20 0 0 -26 -26 3 6 -9 -8 -12 -11 -16 -15 0 0 -20 -19 0 0 -25 -24 0 0 -32 -31 6 10 -12 -9 -16 -13 -20 -17 0 0 -25 -22 0 0 -31 -28 0 0 -39 -36 10 14 -15 -11 -20 -16 -25 -21 0 0 -30 -26 0 0 -37 -33 0 0 -47 -43 14 18 -15 -11 -20 -16 -25 -21 0 0 -30 -26 -36 -32 -42 -38 0 0 -57 -53 18 24 -18 -14 -24 -20 -31 -27 0 0 -37 -33 -43 -39 -50 -46 -59 -55 -69 -65 24 30 -18 -14 -24 -20 -31 -27 -37 -33 -44 -40 -51 -47 -60 -56 -71 -67 -84 -80 30 40 -21 -17 -29 -25 -38 -34 -43 -39 -55 -51 -63 -59 -75 -71 -89 -85 -107 -103 40 50 -21 -17 -29 -25 -38 -34 -49 -45 -65 -61 -76 -72 -92 -88 -109 -105 -131 -127 50 65 -26 -21 -35 -30 -47 -42 -60 -55 -81 -76 -96 -91 -116 -111 -138 -133 -166 -161 65 80 -26 -21 -37 -32 -53 -48 -69 -64 -96 -91 -114 -109 -140 -135 -168 -163 -204 -199 80 100 -30 -24 -44 -38 -64 -58 -84 -78 -117 -111 -139 -133 -171 -165 -207 -201 -251 -245 100 120 -30 -24 -47 -41 -72 -66 -97 -91 -137 -131 -165 -159 -203 -197 -247 -241 -303 -297 120 140 -36 -28 -56 -48 -85 -77 -115 -107 -163 -155 -195 -187 -241 -233 -293 -285 -358 -350 140 160 -36 -28 -58 -50 -93 -85 -127 -119 -183 -175 -221 -213 -273 -265 -333 -325 -408 -400 160 180 -36 -28 -61 -53 -101 -93 -139 -131 -203 -195 -245 -237 -303 -295 -373 -365 -458 -450 180 200 -41 -33 -68 -60 -113 -105 -157 -149 -227 -219 -275 -267 -331 -323 -416 -408 -511 -503 200 225 -41 -33 -71 -63 -121 -113 -171 -163 -249 -241 -301 -293 -376 -368 -461 -453 -566 -558 225 250 -41 -33 -75 -67 -131 -123 -187 -179 -275 -267 -331 -323 -416 -408 -511 -503 -631 -623 250 280 -47 -36 -85 -74 -149 -138 -209 -198 -306 -295 -376 -365 -466 -455 -571 -560 -701 -690 280 315 -47 -36 -89 -78 -161 -150 -231 -220 -341 -330 -416 -405 -516 -505 -641 -630 -781 -770 315 355 -51 -41 -97 -87 -179 -169 -257 -247 -379 -369 -464 -454 -579 -569 -719 -709 -889 -879 355 400 -51 -41 -103 -93 -197 -187 -283 -273 -424 -414 -519 -509 -649 -639 -809 -799 -989 -979 400 450 -55 -45 -113 -103 -219 -209 -317 -307 -477 -467 -582 -572 -727 -717 -907 -897 -1087 -1077 450 500 -55 -45 -119 -109 -239 -229 -347 -337 -527 -517 -647 -637 -807 -797 -987 -977 -1237 -1227
ISO Shaft Tolerances (ISO 286-2)(3mm-400mm):
ISO Shaft Tolerances for chart given below shows range between 3mm to 400mm. Nominal Dimension and Tolerance Zone for Holes are in mm (Metric). ISO Shaft Tolerances help the manufacturer to machine the parts with specified limits given by engineer. ISO Shaft Tolerance limits is designated with lower case letter as shown in the chart and It is also described in previous pages.
Example: Nominal Size 3mm-6mm; -270m= -270(10-3
)=-0.270mm
GradNOMINAL SHAFT SIZES (mm)
-
e
Over 3 6 10 18 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355
Up to
and
incl. 6 10 18 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355 400
a12
-
270
-
390
-
280
-
430
-
290
-
470
-300
-510
-
310
-
560
-
320
-
570
-
340
-
640
-
360
-
660
-
380
-
730
-
410
-
760
-
460
-
860
-
520
-
920
-
580
-
980
-660
-
1120
-
740
-
1200
-
820
-
128
0
-
920
-
144
0
-
1050
-
1570
-
1200
-
1770
-
135
0
-
192
0
d6
-30
-38
-40
-49
-50
-61
-65
-78
-80
-96
-100
-119
-120
-142
-145
-170
-170
-199
-190
-222
-210
-246
e6
-20
-28
-25
-34
-32
-43
-40
-53
-50
-66
-60
-79
-72
-94
-85
-110
-100
-129
-110
-142
-125
-161
e13
-20
-
200
-25
-
245
-32
-
302
-40
-370
-50
-440
-60
-520
-72
-612
-85
-715
-100
-820
-110
-920
-125
-1015
f5
-10
-15
-13
-19
-16
-24
-20
-29
-25
-36
-30
-43
-36
-51
-43
-61
-50
-70
-56
-79
-62
-87
f6
-10
-18
-13
-22
-16
-27
-20
-33
-25
-41
-30
-49
-36
-58
-43
-68
-50
-79
-56
-88
-62
-98
f7
-10
-22
-13
-28
-16
-34
-20
-41
-25
-50
-30
-60
-36
-71
-43
-83
-50
-96
-56
-108
-62
-119
g5
-4
-9
-5
-11
-6
-14
-7
-16
-9
-20
-10
-23
-12
-27
-14
-32
-15
-35
-17
-40
-18
-43
g6
-4
-12
-5
-14
-6
-17
-7
-20
-9
-25
-10
-29
-12
-34
-14
-39
-15
-44
-17
-49
-18
-54
g7
-4
-16
-5
-20
-6
-24
-7
-28
-9
-34
-10
-40
-12
-47
-14
-54
-15
-61
-17
-69
-18
-75
h4
0
-4
0
-4
0
-5
0
-6
0
-7
0
-8
0
-10
0
-12
0
-14
0
-16
0
-18
h5
0
-5
0
-6
0
-8
0
-9
0
-11
0
-13
0
-15
0
-18
0
-20
0
-23
0
-25
h6
0
-8
0
-9
0
-11
0
-13
0
-16
0
-19
0
-22
0
-25
0
-29
0
-32
0
-36
h7 0 0 0 0 0 0 0 0 0 0 0
-
-12 -15 -18 -21 -25 -30 -35 -40 -46 -52 -57
h8
0
-18
0
-22
0
-27
0
-33
0
-39
0
-46
0
-54
0
-63
0
-72
0
-81
0
-89
h9
0
-30
0
-36
0
-43
0
-52
0
-62
0
-74
0
-87
0
-100
0
-115
0
-130
0
-140
h10
0
-48
0
-58
0
-70
0
-84
0
-100
0
-120
0
-140
0
-160
0
-185
0
-210
0
-230
h11
0
-75
0
-90
0
-
110
0
-130
0
-160
0
-190
0
-220
0
-250
0
-290
0
-320
0
-360
h12
0
-
120
0
-
150
0
-
180
0
-210
0
-250
0
-300
0
-350
0
-400
0
-460
0
-520
0
-570
j5
+3
-2
+4
-2
+5
-3
+5
-4
+6
-5
+6
-7
+6
-9
+7
-11
+7
-13
+7
-16
+7
-18
j6
+6
-2
+7
-2
+8
-3
+9
-4
+11
-5
+12
-7
+13
-9
+14
-11
+16
-13
+16
-16
+18
-18
j7
+8
-4
+10
-5
+12
-6
+13
-8
+15
-10
+18
-12
+20
-15
+22
-18
+25
-21
+26
-26
+29
-28
js5
+2.
5
-2.5
+3
-3
+4
-4
+4.5
-4.5
+5.5
-5.5
+6.5
-6.5
+7.5
-7.5
+9
-9
+10
-10
+11.5
-11.5
+12.5
-12.5
js6
+4
-4
+4.
5
-4.5
+5.
5
-5.5
+6.5
-6.5
+8
-8
+9.5
-9.5
+11
-11
+12.5
-12.5
+14.5
-14.5
+16
-16
+18
-18
js7
+6
-6
+7.
5
-7.5
+9
-9
+10.5
-10.5
+12.5
-12.5
+15
-15
+17.5
-17.5
+20
-20
+23
-23
+26
-26
+28.5
-28.5
k5
+6
+1
+7
+1
+9
+1
+11
+2
+13
+2
+15
+2
+18
+3
+21
+3
+24
+4
+27
+4
+29
+4
k6
+9
+1
+10
+1
+12
+1
+15
+2
+18
+2
+21
+2
+25
+3
+28
+3
+33
+4
+36
+4
+40
+4
k7
+13
+1
+16
+1
+19
+1
+23
+2
+27
+2
+32
+2
+38
+3
+43
+3
+50
+4
+56
+4
+61
+4
m5 +9
+12
+15
+17 +20 +24 +28 +33 +37 +43 +46
-
+4 +6 +7 +8 +9 +11 +13 +15 +17 +20 +21
m6
+12
+4
+15
+6
+18
+7
+21
+8
+25
+9
+30
+11
+35
+13
+40
+15
+46
+17
+52
+20
+57
+21
m7
+16
+4
+21
+6
+25
+7
+29
+8
+34
+9
+41
+11
+48
+13
+55
+15
+63
+17
+72
+20
+78
+21
n5
+13
+8
+16
+10
+20
+12
+24
+15
+28
+17
+33
+20
+38
+23
+45
+27
+51
+31
+57
+34
+62
+37
n6
+16
+8
+19
+10
+23
+12
+28
+15
+33
+17
+39
+20
+45
+23
+52
+27
+60
+31
+66
+34
+73
+37
n7
+20
+8
+25
+10
+30
+12
+36
+15
+42
+17
+50
+20
+58
+23
+67
+27
+77
+31
+86
+34
+94
+37
p5
+17
+12
+21
+15
+26
+18
+31
+22
+37
+26
+45
+32
+52
+37
+61
+43
+70
+50
+79
+56
+87
+62
p6
+20
+12
+24
+15
+29
+18
+35
+22
+42
+26
+51
+32
+59
+37
+68
+43
+79
+50
+88
+56
+98
+62
r6
+23
+15
+28
+19
+34
+23
+41
+28
+50
+34
+60
+41
+62
+43
+73
+51
+76
+54
+8
8
+6
3
+90
+65
+93
+68
+106
+77
+10
9
+80
ISO Shaft Tolerances (ISO 286-2) (400mm-3150mm):
ISO Shaft Tolerances for chart given below shows range between 400mm to 3150mm. Nominal Dimension and Tolerance Zone for Holes are in mm (Metric). ISO Shaft Tolerances help the manufacturer to machine the parts with specified limits given by engineer. ISO Shaft Tolerance limits is designated with lower case letter as shown in the chart and It is also described in previous pages.
Example: Nominal Size 400mm-500mm;-135m= -135x(10-3
)=-0.135mm
Grade NOMINAL SHAFT SIZES (mm)
-
Over 400 500 630 800 1000 1250 1600 2000 2500
Up To And Incl. 500 630 800 1000 1250 1600 2000 2500 3150
e6
-135
-175
- 145
-189
-160
-210
-170
- 226
-195
-261
-220
-298
-240
-332
-260
-360
-290
-420
e7
-135
-198
-145
-215
-160
- 240
-170
-260
-195
-300
-345
-220
-240
-390
-260
-435
-290
-500
e8
-135
- 232
-145
-255
-160
-285
-170
-310
-195
-360
-220
415
-240
-470
-260
-540
-290
-620
e9
-135
-290
-145
-320
-160
-360
-170
-400
-195
-455
- 220
-530
-240
- 610
-260
-700
-290
-830
e10
-135
-385
-145
-425
-160
-480
- 170
- 530
-195
-615
-220
-720
-240
-840
-260
-960
-290
-1150
f6
-68
-108
-76
-120
-80
-130
-86
--142
-98
-164
-110
- 188
-120
-212
-130
-240
-145
-280
f7
-68
-131
-76
-146
-80
- 160
-86
- 176
-98
- 203
-110
- 235
-120
-270
-130
-305
-145
-355
f8
-68
-165
-76
- 186
-80
-205
-86
- 226
-98
-263
-110
-305
-120
-350
-130
-410
-145
-475
g6
-20
-60
-22
-66
-24
-74
-26
-82
-28
-94
-30
-108
-32
-124
-34
-144
-38
-173
g7
-20
-83
-22
-92
-24
- 104
-26
-116
-28
-133
-30
- 155
-32
-182
-34
-209
-38
-248
g8
-20
-117
-22
-132
-24
- 149
-26
-166
-28
-193
-30
-225
-32
-262
-34
-314
-38
-368
h6
0
-40
0
-44
0
-50
0
-56
0
-66
0
-78
0
-92
0
-110
0
-135
h7
0
-63
0
-70
0
- 80
0
- 90
0
-105
0
- 125
0
-150
0
-175
0
-210
h8
0
-97
0
-110
0
-125
0
-140
0
-165
0
-195
0
-230
0
- 280
0
-330
h9
0
-155
0
-175
0
-200
0
-230
0
-260
0
-310
0
-370
0
- 440
0
-540
h10
0
-250
0
-280
0
-320
0
-360
0
-420
0
-500
0
-600
0
-700
0
-860
-
h11
0
-400
0
-440
0
-500
0
-560
0
-660
0
-780
0
-920
0
-1100
0
-1350
jS6
+20
-20
+22
-22
+25
-25
+28
-28
+33
-33
+39
-39
+46
-46
+55
-55
+67.5
-67.5
jS7
+31.5
-31.5
+35
-35
+40
-40
+45
-45
+52.5
-52.5
+62.5
-62.5
+-75
-75
+87.5
-87.5
+105
-105
jS8
+48.5
-48.5
+55
-55
+62.5
-62.5
+70
-70
+82.5
-82.5
+97.5
-97.5
+-115
-115
+140
-140
+165
-165
k6
+45
+4
+44
+ 0
+50
0
+ 56
0
+66
0
+78
0
+92
0
+110
0
+135
0
k7
+68
+5
+ 70
0
+80
0
+ 90
0
+105
0
+125
0
+ 150
0
175
0
+210
0
k8
+97
0
+110
0
+125
0
+140 0
0
+165
0
+195
0
+230
0
+280
0
+330
0
m6
+63
+23
+70
+26
+80
+30
+90
+34
+106
+40
+126
+48
+150
+58
+178
+68
+211
+76
m7
+86
+23
+96
+26
+110
+30
+124
+34
+145
+ 40
+173
+48
+208
+58
+243
+68
+286
+ 76
n6
+80
+40
+88
+44
+100
+ 50
+112
+56
+132
+ 66
+156
+ 78
+184
+ 92
+ 220
+ 110
+270
+ 135
n7
+103
+40
+114
+44
+130
+50
+146
+56
+171
+66
+203
+ 78
+242
+92
+ 285
+110
+345
+ 135
p6
+108
+68
+122
+78
+138
+88
+156
+100
+186
+120
+218
+140
+262
+170
+305
+195
+375
+240
p7
+131
+68
+148
+78
+168
+88
+190
+100
+225
+120
+265
+ 140
+320
+170
+370
+195
+450
+240
p8
+165
+68
+188
+78
+213
+ 88
+240
+100
+ 285
+120
+335
+140
+400
+170
+ 475
+195
+570
+240
ISO Hole Tolerances (ISO 286-2) (3mm-400mm):
ISO Hole Tolerances for chart given below shows range between 3mm to 400mm. Nominal Dimension and Tolerance Zone for Holes are in mm (Metric). ISO Hole Tolerances help the manufacturer to machine the parts with specified litims given by engineer. ISO Hole Tolerance limits is designated with Capital Letter as shown in the chart and It is also described in previous pages.
-
Example: Nominal Size 3mm-6mm; 28m = 28x(10-3
)=0.028mm
Grade NOMINAL HOLE SIZES (mm)
over 3 6 10 18 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355
inc. 6 10 18 30 40 50 65 80 100 120 140 160 180 200 225 250 280 315 355 400
E6
+28
+20
+34
+25
+43
+32
+53
+40
+66
+50
+79
+ 60
+94
+72
+110
+85
+129
+100
+142
+110
+161
+125
E7
+32
+20
+40
+25
+50
+32
+61
+40
+75
+50
+90
+ 60
+107
+72
+125
+85
+146
+100
+162
+110
+185
+125
E11
+95
+20
+115
+25
+142
+32
+170
+40
+210
+50
+250
+ 60
+292
+72
+335
+85
+390
+100
+430
+110
+485
+125
E12
+140
+20
+175
+25
+212
+32
+250
+40
+300
+50
+360
+ 60
+422
+72
+485
+85
+560
+100
+630
+110
+695
+125
E13
+200
+20
+245
+25
+302
+32
+370
+40
+440
+50
+520
+ 60
+612
+72
+715
+85
+820
+100
+920
+110
+1 015
+125
F6
+18
+10
+22
+13
+27
+16
+33
+20
+41
+25
+49
+ 30
+58
+36
+68
43
+79
+50
+88
+56
+98
+62
F7
+22
+10
+28
+13
+34
+16
+41
+20
+50
+25
+60
+ 30
+71
+36
+83
43
+96
+50
+108
+56
+119
+62
F8
+28
+10
+35
+13
+43
+16
+53
+20
+64
+25
+76
+ 30
+90
+36
+106
43
+122
+50
+137
+56
+151
+62
G6
+12
+4
+14
+5
+17
+6
+20
+7
+25
+9
+29
+10
+34
+ 12
+39
+14
+44
+15
+49
+17
+54
+18
G7
+16
+4
+20
+5
+24
+6
+28
+7
+34
+9
+40
+10
+47
+ 12
+54
+14
+61
+15
+69
+17
+75
+18
G8
+22
+4
+27
+5
+33
+6
+40
+7
+48
+9
+56
+10
+66
+ 12
+77
+14
+87
+15
+98
+17
+107
+18
H6
+8
0
+9
0
+11
0
+13
0
+16
0
+19
0
+22
0
+25
0
+29
0
+32
0
+36
0
H7
+12
0
+15
0
+18
0
+21
0
+25
0
+30
0
+35
0
+40
0
+46
0
+52
0
+57
0
H8
+18
0
+22
0
+27
0
+33
0
+39
0
+46
0
+54
0
+63
0
+72
0
+81
0
+89
0
H9
+30
0
+36
0
+43
0
+52
0
+62
0
+74
0
+87
0
+100
0
+115
0
+130
0
+140
0
-
H10
+48
0
+58
0
+70
0
+84
0
+100
0
+120
0
+140
0
+160
0
+185
0
+210
0
+230
0
H11
+75
0
+90
0
+110
0
+130
0
+160
0
+190
0
+220
0
+250
0
+290
0
+320
0
+360
0
J6
+5
-3
+5
-4
+6
-5
+8
-5
+10
-6
+13
-6
+16
-6
+18
-7
+22
-7
+25
-7
+29
-7
J7
+6
-6
+8
-7
+10
-8
+12
-9
+14
-11
+18
-12
+22
-13
+26
-14
+30
-16
+36
-16
+39
-18
J8
+10
-8
+12
-10
+15
-12
+20
-13
+24
-15
+28
-18
+34
-20
+41
-22
+47
-25
+55
-26
+60
-29
JS6
+4
-4
+4.5
-4.5
+5.5
-5.5
+6.5
-6.5
+8
-8
+9.5
-9.5
+11
-11
+12.5
-12.5
+14.5
-14.5
+16
-16
+18
-18
JS7
+6
-6
+7.5
-7.5
+9
-9
+10.5
-10.5
+12.5
-12.5
+15
-15
+17.5
-17.5
+20
-20
+23
-23
+26
-26
+28.5
-28.5
JS8
+9
-9
+11
-11
+13.5
-13.5
+16.5
-16.5
+19.5
-19.5
+23
-23
+27
-27
+31.5
-31.5
+36
-36
+40.5
-40.5
+44.5
-44.5
K6
+2
-6
+2
-7
+2
-9
+2
-11
+3
-13
+4
-15
+4
-18
+4
-21
+5
-24
+5
-27
+7
-29
K7
+3
-9
+5
-10
+6
-12
+6
-15
+7
-18
+9
-21
+10
-25
+12
-28
+13
-33
+16
-36
+17
-40
K8
+5
-13
+6
-16
+8
-19
+10
-23
+12
-27
+14
-32
+16
-38
+20
-43
+22
-50
+25
-56
+28
-61
M6
-1
-9
-3
-12
-4
-15
-4
-17
-4
-20
-5
-24
-6
-28
-8
-33
-8
-37
-9
-41
-10
-46
M7
0
-12
0
-15
0
-18
0
-21
0
-25
0
-30
0
-35
0
-40
0
-46
0
-52
0
-57
M8
+2
-16
+1
-21
+2
-25
+4
-29
+5
-34
+5
-41
+6
-48
+8
-55
+9
-63
+9
-72
+11
-78
N6
-5
-13
-7
-16
-9
-20
-11
-24
-12
-28
-14
-33
-16
-38
-20
-45
-22
-51
-25
-57
-26
-62
N7
-4
-16
-4
-19
-5
-23
-7
-28
-8
-33
-9
-39
-10
-45
-12
-52
-14
-60
-14
-66
-16
-73
N8
-2
-20
-3
-25
-3
-30
-3
-36
-3
-42
-4
-50
-4
-58
-4
-67
-5
-77
-5
-86
-5
-94
P6
-9
-17
-12
-21
-15
-26
-18
-31
-21
-37
-26
-45
-30
-52
-36
-61
-41
-70
-47
-79
-51
-87
-
P7
-8
-20
-9
-24
-11
-29
-14
-35
-17
-42
-21
-51
-24
-59
-28
-68
-33
-79
-36
-88
-41
-98
P8
-12
-30
-15
-37
-18
-45
-22
-55
-26
-65
-32
-78
-37
-91
-43
-106
-50
-122
-56
-137
-62
-151
R6
-12
-20
-16
-25
-20
-31
-24
-37
-29
-45
-35
-54
-37
-56
-44
-66
-47
-69
-56
-81
-58
-83
-61
-86
-68
-97
-71
-100
-75
-104
-85
-117
-89
-121
-97
-133
-103
-139
R7
-11
-23
-13
-28
-16
-34
-20
-41
-25
-50
-30
-60
-32
-62
-38
-73
-41
-76
-48
-88
-50
-90
-53
-93
-60
-106
-63
-109
-67
-113
-74
-126
-78
-130
-87
-144
-93
-150
ISO Hole Tolerances (ISO 286-2) (400mm to 3150mm):
ISO Hole Tolerances for chart given below shows range between 400mm to 3150mm. Nominal Dimension and Tolerance Zone for Holes are in mm (Metric). ISO Hole Tolerances help the manufacturer to machine the parts with specified limits given by engineer. ISO Hole Tolerance limits is designated with Capital Letter as shown in the chart and It is also described in previous pages.
Example: Nominal Size 400mm-500mm; 175m= 175x(10-3
)=0.175mm
Grade NOMINAL HOLE SIZES (mm)
Over 400 500 630 800 1000 1250 1600 2000 2500
Up To And Incl. 500 630 800 1000 1250 1600 2000 2500 3150
E6
+175
+135
+189
+ 145
+210
+160
+ 226
+170
+261
+195
+298
+220
+332
+240
+360
+260
+420
+290
E7
+198
+135
+215
+145
+ 240
+160
+260
+170
+300
+195
+345
+220
+390
+240
+435
+260
+500
+290
E8
+ 232
+135
+255
+145
+285
+160
+310
+170
+360
+195
+415
+220
+470
+240
+540
+260
+620
+290
E9
+290
+135
+320
+145
+360
+160
+400
+170
+455
+195
+530
+ 220
+ 610
+240
+700
+260
+830
+290
E10
+385
+135
+425
+145
+480
+160
+ 530
+ 170
+615
+195
+720
+220
+840
+240
+960
+260
+1150
+290
-
F6
+108
+68
+120
+76
+130
+80
+142
+86
+164
+98
+ 188
+110
+212
+120
+240
+130
+280
+145
F7
+131
+68
+146
+76
+ 160
+80
+ 176
+86
+ 203
+98
+ 235
+110
+270
+120
+305
+130
+355
+145
F8
+165
+68
+ 186
+76
+205
+80
+ 226
+86
+263
+98
+305
+110
+350
+120
+410
+130
+475
+145
G6
+60
+20
+66
+22
+74
+24
+82
+26
+94
+28
+108
+30
+124
+32
+144
+34
+173
+38
G7
+83
+20
+92
+22
+ 104
+24
+116
+26
+133
+28
+ 155
+30
+182
+32
+209
+34
+248
+38
G8
+117
+20
+132
+22
+ 149
+24
+166
+26
+193
+28
+225
+30
+262
+32
+314
+34
+368
+38
H6
+40
0
+44
0
+50
0
+56
0
+66
0
+78
0
+92
0
+110
0
+135
0
H7
+63
0
+70
0
+ 80
0
+ 90
0
+105
0
+ 125
0
+150
0
+175
0
+210
0
H8
+97
0
+110
0
+125
0
+140
0
+165
0
+195
0
+230
0
+ 280
0
+330
0
H9
+155
0
+175
0
+200
0
+230
0
+260
0
+310
0
+370
0
+ 440
0
+540
0
H10
+250
0
+280
0
+320
0
+360
0
+420
0
+500
0
+600
0
+700
0
+860
0
H11
+400
0
+440
0
+500
0
+560
0
+660
0
+780
0
+920
0
+1100
0
+1350
0
JS6
+20
-20
+22
-22
+25
-25
+28
-28
+33
-33
+39
-39
+46
-46
+55
-55
+67.5
-67.5
JS7
+31.5
-31.5
+35
-35
+40
-40
+45
-45
+52.5
-52.5
+62.5
-62.5
+75
-75
+87.5
-87.5
+105
-105
JS8
+48.5
-48.5
+55
-55
+62.5
-62.5
+70
-70
+82.5
-82.5
+97.5
-97.5
+115
-115
+140
-140
+165
-165
K6
+8
-32
+ 0
-44
+ 0
-50
+ 0
- 56
+ 0
-66
+ 0
-78
+ 0
-92
+ 0
-110
+ 0
-135
K7
+18
-45
+0
-70
+ 0
-80
+ 0
-90
+ 0
-105
+ 0
-125
+ 0
-150
+ 0
-175
+ 0
-210
K8
+ 29
-68
+ 0
-110
+ 0
-125
+ 0
-140
+ 0
-165
+ 0
-195
+ 0
-230
+ 0
-280
+ 0
-330
-
M6
-10
-50
-26
-70
-30
-80
-34
-90
-40
-106
-48
-126
-58
-150
-68
-178
-76
-211
M7
0
-63
-26
-96
-30
-110
-34
-124
-40
-145
-48
-173
-58
-208
-68
-243
-76
-286
M8
+ 11
-86
-26
-136
-30
-155
-34
-174
-40
-205
-48
-243
-58
-288
-68
-348
-76
-406
N6
-27
-67
-44
-88
-50
-100
-56
- 112
-66
-132
-78
-156
-92
-184
-110
- 220
-135
-270
N7
-17
-80
-44
-114
-50
-130
-56
- 146
-66
-171
-78
-203
-92
-242
-110
- 285
-135
-345
N8
-6
-103
-44
-154
-50
-175
-56
- 196
-66
-231
-78
-273
-92
-322
-110
-390
-135
-465
P6
-55
-95
-78
-122
-88
-138
-100
-156
-120
- 186
-140
-218
-170
-262
-195
-305
-240
-375
P7
-45
-108
-78
-148
-88
-168
-100
- 190
-120
-225
-140
-265
-170
-320
-195
-370
-240
-450
P8
-68
-165
-78
-188
-88
-213
-100
-240
-120
- 285
-140
-335
-170
-400
-195
- 475
-240
-57
ANSI Standard Limits and Fits (ANSI B4.1-1967,R1974)
ANSI, This American Standard for preferred limits and fits for cylindrical parts presents definitions of terms applying to fits between nonthreaded cylindrical and makes some recommendations on preferred sizes, fits, tolerances, and allowances for use where they areapplicable. The ANSI B4.1 charts data are provided in thousandths (.001) of an inch. ANSI can be defined ANSI metric or ANSI Inch system. ANSI decimal inch system is based on ANSI Standard (B4.1 - 1967(1979). ANSI Standard (B4.2 - 1978)metric system is based on ISO millimeter system. ANSI - American National Standards Institute. ISO is International Organization for Standardization. ANSI standard is in accord with the recommendations of American-British-Canadian (ABC) conferences up to diameter of 20 inches.The ABC proposal comprises:(a)A grade system of fundamental tolerances for diameters 0.04 inch to approximately 20 inches, the tolerance values in each grade being to the diameter by a given law of formula and each grade of tolerance being approximately related to the others in the system in a preferred number ratio (R5 series, with 60 percent increments). (a) A series of unilateral hole limits derived from the fundamental tolerances, for use with a hole basis system. (c) A series of shaft, one of these limits being determined by the allowance ( according to some technical requirement), the other being derived from it by addition or subtraction of the fundamental tolerance.(d) A selection of fits made by recommended association of certain of the holes and shaft, the selection being adequate to cover most engineering requirements.
What can be effective for selection of the fits? Many factor can be affective for selecting proper fits such as bearing loads, speed, materials, length of
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engagement, lubrication, humidity, and temperature etc. This all affect must be taken into consideration in the selection of the fits for proper applications.
ANSI B4.1 - 1967(1979), R1974 Standard Tolerances
ANSI B4.1 standard implements 10 tolerance grades to meet the requirements of various production branches for accuracy of products. ANSI B4.1 standard defines a system of preferred fits only for basic sizes up to 19.69 inch. ANSI B4.1 system of tolerances is prescribed by the standard for basic sizes up to 200 in. ANSI B4.1 Tolerance Table provides a suitable range from which appropriate tolerance for holes and shaft can be selected. This enables the use of standard gages. Table shown below
NOMINAL( BASIC) SIZES
(INCHES) INTERNATIONAL TOLERANCE GRADES
OVER UP TO INCL. IT4 IT5 IT6 IT7 IT8 IT9 IT10 IT11 IT12 IT13
0 0.12 0.12 0.15 0.25 0.4 0.6 1.0 1.6 2.5 4 6
0.12 0.24 0.15 0.20 0.3 0.5 0.7 1.2 1.8 3.0 5 7
0.24 0.40 0.15 0.25 0.4 0.6 0.9 1.4 2.2 3.5 6 9
0.40 0.71 0.2 0.3 0.4 0.7 1.0 1.6 2.8 4.0 7 10
0.71 1.19 0.25 0.4 0.5 0.8 1.2 2.0 3.5 5.0 8 12
1.19 1.97 0.3 0.4 0.6 1.0 1.6 2.5 4.0 6 10 16
1.97 3.15 0.3 0.5 0.7 1.2 1.8 3.0 4.5 7 12 18
3.15 4.73 0.4 0.6 0.9 1.4 2.2 3.5 5 9 14 22
4.73 7.09 0.5 0.7 1.0 1.6 2.5 4.0 6 10 16 25
7.09 9.85 0.6 0.8 1.2 1.8 2.8 4.5 7 12 18 28
9.85 12.41 0.6 0.9 1.2 2.0 3.0 5.0 8 12 20 30
12.41 15.75 0.7 1.0 1.4 2.2 3.5 6 9 14 22 35
15.75 19.69 0.8 1.0 1.63 2.5 4 6 10 16 25 40
19.69 30.09 0.9 1.2 2.0 3 5 8 12 20 30 50
30.09 41.49 1.0 1.6 2.5 4 6 10 16 25 40 60
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41.49 56.19 1.2 2.0 3 5 8 12 20 30 50 80
56.19 76.39 1.6 2.5 4 6 10 16 25 40 60 100
76.39 100.9 2.0 3 5 8 12 20 30 50 80 125
100.9 131.9 2.5 4 6 10 16 25 40 60 100 160
131.9 171.9 3 5 8 12 20 30 50 80 125 200
131.9 200 4 6 10 16 25 40 60 100 160 250
Tolerances in Thousandths of an Inch. All tolerances above the Blue line are in accordance with ABC (American-British, Canadian) agreements.
ANSI B4.1 - 1967(1979), R1974 Standard Preferred Basic Sizes
All given dimensions in table are in inches. Based on ANSI B4.1, basic size of all mating parts should be chosen from the fractional and decimal series in the table below.
Fractional Decimal Fractional Decimal Fractional Decimal
1/64 0.015625 2-1/4 2.2500 9-1/2 9.5000
1/32 0.03125 2-1/2 2.500 10 10.000
1/16 0.0625 2-3/4 2.7500 10-1/2 10.500
3/32 0.09375 3 3.000 11 11.0000
1/8 0.1250 3-1/4 3.2500 11-1/2 11.5000
5/32 0.15625 3-1/2 3.500 12 12.0000
3/16 0.1875 3-3/4 3.7500 12-1/2 12.5000
1/24 0.2500 4 4.000 13 13.000
5/16 0.3125 4-1/4 4.2500 13-1/2 13.5000
3/8 0.3750 4-1/2 4.5000 14 14.0000
7/16 0.4375 4-3/4 4.7500 14-1/2 14.5000
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1/2 0.5000 5 5.000 15 15.0000
9/16 0.5625 5-1/4 5.2500 15-1/2 15.5000
5/8 0.6250 5-1/2 5.500 16 16.0000
11/16 0.6875 5-3/4 5.7500 16-1/2 16.5000
3/4 0.7500 6 6.000 17 17.000
7/8 0.8750 6-1/2 6.500 17-1/2 17.5000
1 1.0000 7 7.000 18 18.0000
1-1/4 1.2500 7-1/2 7.500 18-1/2 18.5000
1-1/2 1.500 8 8.000 19 19.0000
1-3/4 1.7500 8-1/2 8.500 19-1/2 19.5000
2 2.000 9 9.000 20 20.0000
ANSI B4.1 - 1967(1979), R1974 Standard Fit Designations
ANSI B4.1 Standard arranged fits classes in three general groups according to the field and type of usage. Standard fits are designated by means of some symbols which facilitate reference to classes of fits to get better understanding. The symbols are not intended to be shown on the manufacturing detail drawings, only sizes should be specified on the detail drawings.
1-) Running or Sliding Fits [RC]
2-) Locational Fits [LC, LT, LN]. This standard can be explained in three groups.
a-) Clearance Locational Fits [LC]
b-) Transition Locational Fits [LT]
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c-) Interference Locational Fits [LN]
3-) Force or Shrink Fits [FN]
These letter symbols RC, LC, LT, LN, and FN are used with numbers representing the fit class. like RC4 represent class 4. One of these symbols "with two letter and one number" represent a complete fit. This fit can be interference, in and max clearance, and limits of sizes for mating parts.
1-) Running And Sliding Fits (RC):
Running and Sliding fits ranges are designated with RC1 to RC9.Throughout the range of the sizes limits of clearance for this fit are intended to provide a running performance with suitable lubrication allowance. Loosest of the class fits, used when a shaft is must move freely inside a hole or bearing, and the positioning of the shaft is not critical in this fit like sliding gears and clutch disks, pivots, running and sliding fits of shafts, guiding bushings, pistons of hydraulic machines, etc. There are nine such fits RC1 to RC9. The lower RC numbers are the tighter fits, the higher numbers are the looser fits. RC1 to RC9 Fits may be described as follows;
RC1; Close Sliding Fits: This kind of fits are intended for the accurate location of parts which must assemble without noticeable play.
RC2; Sliding Fits: This kind of fits are intended for the accurate location but with greater maximum clearance than class RC1. Parts made to this fit turn and move easily. This type is not designed for free run. Sliding fits in larger sizes may seize with small temperature changes.
RC3; Precision Running Fits: This kind of fits are about the closest fits which can be expected to run freely. Precision running fits are intended for precision work at low speed, low bearing pressures, and light journal pressures. RC3 is not suitable where noticeable temperature differences occur.
RC4; Close Running Fits: This kind of fits are mostly for running fits on accurate machinery with moderate surface speed, bearing pressures, and journal pressures where accurate location and minimum play are desired. This kind of fits also can be described as smaller clearances with higher requirements for precision fit.
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RC5 and R6; Medium Running Fits: This kind of fits are designed for machines running at higher running speeds, considerable bearing pressures, and heavy journal pressure. This kind of fits also can be described with greater clearances with common requirements for fit precision.
RC7; Free Running Fits: This kind of fits are intended to use where accuracy is not essential. It is suitable for great temperature variations. This fits are suitable to use without any special requirements for precise guiding of shafts.
RC8 and RC9; Loose Running Fits: This kind of fits are intended for use where wide commercial tolerances may be required on the shaft. With this fits, The parts with great clearances with having great tolerances. Loose running fits exposed to effects of corrosion, contamination by dust and thermal or mechanical deformations.
Graphical Representation of ANSI B4.1-1967 Running and Sliding Fits Table
Running and Sliding Limits and Fits For Cylindrical Parts [(ANSI B4.1-1967,R1987)]
All limits shown in chart below are in thousandths of an inches. Symbols H5,g5, etc. are Shaft and Hole designations used in American-British-Canadian System (ABC). Limits for Shaft and Hole are applied
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algebraically to the Nominal (basic) size to obtain the limits of the size for the parts. All data given in bold in the chart below are in accordance with ABC agreements. The values given under the "Clearance Limits Column" represent min and max amounts of clearance resulting from application of standard tolerance limits.
VALUES SHOWN BELOW ARE IN THOUSANDTHS OF AN INCHES
Nominal
(Basic) Size
Ranges
(Inches)
Class RC1 Class RC2 Class RC3 Class RC4
Clearance
Limits
Standard
Tolerance
Limits
Clearance
Limits
Standard
Tolerance
Limits
Clearance
Limits
Standard
Tolerance
Limits
Clearance
Limits
Standard
Tolerance
Limits
Over To
Hole
H5
Shaft
g4
Hole
H6
Shaft
g5
Hole
H7
Shaft
f6
Hole
H8
Shaft
f7
0 0.12
0.1
0.45
+0.2
0
-0.1
-0.25
0.1
0.55
+0.25
0
-0.1
-0.3
0.3
0.95
+0.4
0
-0.3
-0.55
0.3
1.3
+0.6
0
-0.3
-0.7
0.12 0.40
0.15
0.5
+0.2
0
-0.15
-0.3
0.15
0.65
+0.3
0
-0.15
-0.35
0.4
1.12
+0.5
0
-0.4
-0.7
0.4
1.6
+0.7
0
-0.4
-0.9
0.24 0.40
0.2
0.6
+0.25
0
-0.2
-0.35
0.2
0.85
+0.4
0
-0.2
-0.45
0.5
1.5
+0.6
0
-0.5
-0.9
0.5
2.0
+0.9
0
-0.5
-1.1
0.40 0.71
0.25
0.75
+0.3
0
-0.25
-0.45
0.25
0.95
+0.4
0
-0.25
-0.55
0.6
1.7
+0.7
0
-0.6
-1.0
0.6
2.3
+1.0
0
-0.6
-1.3
0.71 1.19
0.3
0.95
+0.4
0
-0.3
-0.55
0.3
1.2
+0.5
0
-0.3
-0.7
0.8
2.1
+0.8
0
-0.8
-1.3
0.8
2.8
+0.2
0
-0.8
-1.6
1.19 1.97
0.4
1.1
+0.4
0
-0.4
-0.7
0.4
1.4
+0.6
0
-0.4
-0.8
1.0
2.6
+1.0
0
-1.0
-1.6
1.0
3.6
+1.6
0
-1.0
-2.0
1.97 3.15
0.4
0.2
+0.5
0
-0.4
-0.7
0.4
1.6
+0.7
0
-0.4
-0.9
1.2
3.1
+1.2
0
-1.2
-1.9
1.2
4.2
+1.8
0
-1.2
-2.4
3.15 4.73
0.5
1.5
+0.6
0
-0.5
-0.9
0.5
2.0
+0.9
0
-0.5
-1.1
1.4
3.7
+1.4
0
-1.4
-2.3
1.4
5.0
+2.2
0
-1.4
-2.8
4.73 7.09
0.6
1.8
+0.7
0
-0.6
-1.1
0.6
2.3
+1.0
0
-0.6
-1.3
1.6
4.2
+1.6
0
-1.6
-2.6
1.6
5.7
+2.5
0
-1.6
-3.2
7.09 9.85
0.6
2.0
+0.8
0
-0.6
-1.2
0.6
2.6
+1.2
0
-0.6
-1.4
2.0
5.0
+1.8
0
-2.0
-3.2
2.0
6.6
+2.8
0
-2.0
-3.8
9.85 12.41
0.8
2.3
+0.9
0
-0.8
-1.4
0.8
2.9
+1.2
0
-0.8
-1.7
2.5
5.7
+2.0
0
-2.5
-3.7
2.5
7.5
+3.0
0
-2.5
-4.5
12.41 15.75
1.0
2.7
+1.0
0
-1.0
-1.7
1.0
3.4
+1.4
0
-1.0
-2.0
3.0
6.6
+2.2
0
-3.0
-4.4
3.0
8.7
+3.5
0
-3.0
-5.2
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15.75 19.69
1.2
3.0
+1.0
0
-1.2
-2.0
1.2
3.8
+1.6
0
-1.2
-2.2
4.0
8.1
+2.5
0
-4.0
-5.6
4.0
10.5
+4.0
0
-4.0
-6.5
19.69 30.09
1.6
3.7
+1.2
0
-1.6
-2.5
1.6
4.8
+2.0
0
-1.6
-2.8
5.0
10.0
+3.0
0
-5.0
-7.0
5.0
13.0
+5.0
0
-5.0
-8.0
30.09 41.49
2.0
4.6
+1.6
0
-2.0
-3.0
2.0
6.1