5 tool holders

7/21/2019 5 Tool Holders

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TOOL HOLDERS



Majority of machine tools producing chips

in production shops use a 7/24 taper

(steep) interface between the Spindle &

the Tool holder. This taper found on

Machining Centers & other Machine tools

represents a familiar, widely used & firmly

established Technology.



SPINDLE

INTERFACE

JBS

TAPER

DIN

CAT

MAS STANDARD

DIN STANDARD

CATERPILLAR STANDARD

JAPAN SMALL MACHINE

STANDARD

7/24 TAPER

7/24 TAPER

BT

7/24 TAPER

7/24 TAPER

HSK

KM

NC5

TWO FACE CONTACT

BBT

DIN STANDARD

KENNAMETAL ORIGINAL

NIKKEN ORIGINAL

BIG ORIGINAL

1/10 TAPER

1/10 TAPER

1/10 TAPER



Tool Shank



Drive Slot

Gauge Line

7/24 Taper

V-Groove forTool changer arm Clamping thread

for Pull Stud

Tool Shank



Tool Shank

Advantages :

Not self Locking.

Does not get jammed in the spindle with use.

Kick out device not required to force tool holder out of Spindle.

Allows tool to be held in place & release with simple Draw bar/Pull stud.

Tool holder once tight in the tapered hole of the Spindle, the tool is

secured.

Tool can be held deep with the body of the holder.

Reduces Tool over hang from Spindle face.



Advantages :

Simple & Inexpensive to manufacture

Taper angle; only dimension to be machined with high degree of

precision.

Standardized by ISO, ANSI, DIN, JIS etc.,



Short Comings

Replies on Tapered Surface to play two important role

simultaneously

Taper Surface must precisely locate the tool holder WRT

spindle and provide enough contact between spindle

& tool holder to clamp the tool holder rigidly in position.

Tool Shank



TAPER ANGLE

7 / 24 TAPER

24

7

7 / 24 TAPER

10

1

1/10 TAPER

1 / 10 TAPER



TAPER CONE SIZE

MAS403-1982

BT SHANK 7 / 24 TAPER 48.4

3 1 .

7 5

4 6

65.4

4 4 .

4 5

6 3

101.8

1 0 0

6 9 .

8 5

BT30 BT40 BT50

DIN69893 HSK SHANK 1/10 TAPER

HSK-A100 HSK-A63 HSK-A40

50 32 20

4 0

3 0

1 0 0

7 5

6 3

4 8



Taper Cone Size



Threads for Clamping on Tool ShankSpanner flat for Clamping

Coolant hole for

Through Spindle Coolant

O-Ring

for Coolant sealing

Pull Stud

Spigot Location



Pull Stud



7 / 24 TAPER SHANK

INSTALLATION

UN - CLAMP

CLAMP

DRAWING UNIT COLLET

RETENTION KNOB



HSK is an example of a taper/interface system

developed for high speed machining

HSK Taper



HSK Taper



Advantages :

High static & Dynamic rigidity. Bending load is 30% to 200%

greater than steep Taper holders.

High precision axial & radial reproducibility.

Low mass, low stroke length when tool changing.

Centered clamping with twice the Force

HSK Taper



Rotate the spindle fast enough, and centrifugal force can

cause the interface to open up. When this occurs, the force

of the drawbar pulls the toolholder deeper into the

spindle. This causes the Z offset to change in mid-cycle.

And after the cycle, when the spindle cools down, the

contracting metal can make removing the toolholder

problematic

The HSK tool holder design, which features a

short, hollow taper, addresses this problem with

two features. One is a clamp that pushes on thetool holder from the inside. Centrifugal force at

high speeds actually helps this clamp. The other

feature is contact at two faces-along the taper, and

also along the spindle face.

Difference between BT & HSK



HSK Taper



INSTALLATION

HSK SHANK

UN-CLAMP

CLAMP

SPACE

CONTACT

DRAWING UNIT

COLLET



HSK SHANK LINE-UP

FOR MACHINING CENTER

C YPE

D TYPE

FOR LATHE

E TYPE

F TYPE

FOR HIGH SPEED

B TYPE

FOR HIGH SPEED

A TYPE



BENEFIT FOR USING TWO

FACE CONTACT

SPACE

BT40

CONTACT

A63

F

F

BENDING

BENDING

ø44.45

ø63



SPINDLE THROUGH COOLANT

CENTER THROUGH

RETENTION KNOB WITH HOLE

FLANGE THROUGH

RETENTION KNOB WITHOUT HOLE

SIDE THROUGH

POSITIONING BLOCK

SPINDLE THROUGH



Types of ToolHolders



SIDE LOCK SET SCREW

WELDON SHANK

ADVANTAGES DISADVANTAGES

•Lowest Cost

•Many shops already have

these holders in use

•Difficult to maintain balance

•Not suited for High Speed Machining

Side Lock Holder



COLLET HOLDER

ADVANTAGES

•Good Clamping Force

• Acceptable Concentricity

•Multiple Tool Sizes accepted

•Lower Cost

•Easily Cleaned

DISADVANTAGES

•Concentricity must be verified for

each tool

•Difficult to maintain manufacturers

balance specification•Difficult to seal for Through Spindle

Coolant

•Need Skill Operator

Collet Holder



MILLING CHUCK NEEDLE ROLLER

ADVANTAGES

DISADVANTAGES

•Good Clamping Force

• Acceptable Concentricity

•

Multiple Tool Sizes accepted•Higher rigidity than Collet Chuck

•Moderate Cost

•Easily Cleaned

•Difficult to seal for Through Spindle

Coolant

•Nose diameter will create

interference

•Limited range of tool shanks per

holder

•Special Wrench required to set

torque in order to prevent damage to

holder

Milling Chuck



OIL TANK

ADVANTAGES

• Acceptable Clamping Force

•Excellent Concentricity

•Excellent Balance Characteristics•Positive stop maintains axial

positions to assure maximum

clamping force

•Tool Sizes must match Holder ID

•Normally requires shorter tool

shanks to maintain LDR

•Higher Cost

DISADVANTAGES

Hydraulic Holders



SHRINK FIT HEATING COOLING

Shrink Fit Holders

ADVANTAGES

Excellent Clamping Force

Excellent Concentricity

Excellent Balance CharacteristicsPositive stop maintains axial positions

Small diameter nose minimizesinterference

Short Gage Length



Tool Sizes must match Holder ID (H6 tolerance)

Higher tool cost due to exacting tolerance requirements

Requires External Equipment

Requires more periodic maintenance Higher skill required to change tools

Highest Cost

Do not use HSS shank

DISADVANTAGES

Shrink Fit Holders



Shrink Holder Equipment

MST Kelch



TOOLHOLDER DRILL END • \

MILL TAP

COLLET

HOLDER › › ›

MILLING

CHUCK ¢ › ~

SIDE LOCK ¢ › ~

HYDRAULIC ›

›

~

SHRINK FIT › › ›

:GOOD : BAD : NOTGOOD › ¢ ~



COOLANT THROUGH METHODS

CUTTER THROUGH COOLANT AROUND TOOL

COLLET THROUGHNOZZLE THROUGH



MAXIMUM SPINDLE ROTATION

BT30-CTH10-45 40000min-1

BT40-CTH20-60 20000min-1

BT40-CTH25-75 10000min-1

A100-CTH25-135 15000min-1



ACCURACY

BEARINGS

SCRATCH & CHIPS

RUN-OUT ACCURACY

SCRATCH & CHIPS

SCRATCH & CHIPS

SCRATCH & CHIPS

RUN-OUT ACCURACY

RUN-OUT ACCURACY



INSPECTIONS OF RUNOUT ACCURACY

MACHINE

SPINDLE

TOOL HOLDER

WITHOUT

A COLLET

CUTTER



CHATTERING

SHAPE OF WORKPIECE

CLAMPING

RIGIDITY

CUTTER RIGIDITY

TOOL HOLDER RIGIDITY

SPINDLE RIGIDITY

CHUCKING RIGIDITY

INTERFACE RIGIDITY



Tool Holder Comparison Table

Method

Run Out Rigidity ccess Flexibility Cost pplication Remark

Collet Less 10µm Good Worse Excellent Normal All process Accuracy is

operator dependant

Hydraulic Approx.

4 µm Worse Good N/A Expensive

Except

Roughing

Possible High

Maintenance

Shrink Approx.

3 µm

Excellent Excellent*Less

Costly

All process

H6 Tool Shank

Tolerance required

to AchieveClamping Force

N/A



Holder RunOut Rigid Balance Remarks

Side lock holder 0.01

Mill chucks 0.01

Collet holder 0.005 need skill

Hydraulic holder 0.003 not for rough

Shrink fit holder 0.003 h6 shank

Not Good Acceptable Excellent

Type Holder Characteristic



Through Spindle Coolant

Coolant Supply Source

Retention Knob with O-ring

Must allow coolant

to pass through freely

5 tool holders

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