MICRON CHUCK

Outstanding Clamping power.
Minimal runout.

Why Micron Chuck?

POINT11

HIGH PRECISION MILLING CHUCK

Only Micron Chuck can guarantee such runouts
as 0.001mm at chuck nose and 0.002mm at 3xD.
Micron Chuck was developed utilizing Showa original direct clamping
mechanism and assembling technology acquired in manufacturinghigh quality machine spindles for a long experience.

● How to measure runout
3D POINT
2μｍ

D

CHUCK NOSE
1μｍ

GRADENOSE

3D POINTAA12A

35Tool will be supplied with an inspection sheet.

● Structure of Micron Chuck● Structure of other makers' chuck

Thrust-Ring Tightening Nut Clamping section of bodyTightening NutBall Screw mechanism

Thrust-Ring

1

Thrust-Ring retention bearing

Sliding Thrust-Ring
Torsional stress is caused.

No Torsional stress.

Main body of chuck

Needle rollers

UNCLAMPEDPOSITION

CLAMPEDPOSITION
Face &Taper contact

Main body of chuck

POINT

22Clamping power as high as other milling chucks.
High accuracy Micron Chuck has a high clamping power,too.
The clamping power of ø32 ID Micron chuck is2,450Nm, and ø6 ID 49Nm - about 2 times bigger thanhydraulic chucks.

Standard type Micron Chuck

2,450N•m

POINT

3
3

The cutter is not axially moved by clamping
The cutter is not withdrawn by clamping like collet chucks,
due to its unique mechanism. It is required in mass manufacturing line
to preset cutter length to close tolerance. In case of collet chuck,
the axial cutter projection is shortened by clamping. The back endof the cutter is pressed to the back-up screw at that time, which may
cause bending and breakage of small dimeter cutters.

StableWithdrawn

MICRON CHUCKCOLLET CHUCK2

POINT44Highly balanced and sealed chuck.
Maximum speed :20,000min -1 (Standard HPC-H chuck)
30,000min -1 ("G" type HPC-H chuck)Standard#30,#40
HSK50, 63#50
HSK10010,000min-1

8,000min-1

20,000min-1

12,000min-1

G

30,000min-1－－

15,000min

10,000min-1

AAAAH

M

AA-1

"G" type HPC-H chuck

30,000min-1
POINT

55POINT

66

Thru-the-tool coolant type.
Thru-the-tool coolant type Micron Chucks available.
Please specify it at the time of ordering.

■ Thru-the-tool application

Mechanical chuck, Heater is not required.
Shrink-fit holders have restrictions of cutter material. But,Micron Chucks are applicable to any material of cutters,
keeping high accuracy for a long period of time.

"M" type
Micron Chuck3

POINT

77POINT

88

Wide range of IDs are available.
Standard type, "H" type and "M" type Micron Chucks
covers from ø3mm to ø50mm ID.

Wide application range.
You can extend application range of Micron Chucks byusing straight collets. But, direct chucking is recommended
to obtain the highest performance.

COMPARISON OF RUNOUT & SURFACE FINISH

MICRON CHUCKRunoutHYDRAULIC CHUCKCOLLET CHUCK

3μm at chuck nose,
5μm at 3×D.

N made AA
AA gradecollet : 5μm at 4×D(There is no guarantee at the timeof attaching the holder)

26.5N・m(N made ø6 chuck)

49N・mShowa ø6 collet(10 ID max. holder)

Periodical greasing
since a mechanical chuck.

Periodical check of oilleak required.

Chips must be removed
from collet.

Easy presetting, sincecutter is stable.

Easy presetting, sincecutter is stable.

Cutter is axially moved
by chucking.

AAA grade : 1µm at chuck nose,
2µm at 3×D guranteed.

REMARKS

Micron chuck :Measured runout.
Others : From catalog.

Measure value

Clamping Power

Maintenance

Presetting

φ6φ3249N・m2450N・m

DIMENSIONS[ø6 49N•m] is the maximumof HPC06H long type

BT P.37-44 SK P.100-102 HSK P.109-116
4

Clamping power & Tightening Force
Standard
Chuck size

Clamping
Power（MIN）（N・m)

HPC16780

HPC201180

HPC251760

HPC322450

HPC423920

H-series
Chuck size

Clamping
Power（MIN）（N・m)

HPC03H

10（10）

HPC04H

15（15）

HPC06H

30（20）

HPC08H

40（24）

HPC10H60（35）

HPC12H70（41）

HPC14H80

HPC16H90

Tightening
Force（N・m)

Loosening
Force（N・m)62

40

Tightening
Force（N・m)

Loosening
Force（N・m)

6767※Clamping power of short type chucks (L=75mm max) is shown in ( ).

M-series

NEW

5

Chuck size

Clamping
Power（MIN）（N・m)

HPC03M5

HPC04M7

HPC06M20

HPC08M26

HPC10M33

HPC12M

46

Chuck size

Clamping
Power（MIN）（N・m)

HPC03N2

HPC04N4

HPC06N20

HPC08N26

HPC10N33

HPC12N

46

N-series

Tightening
Force（N・m)

Loosening
Force（N・m)5757

Tightening
Force（N・m)

LooseningForce（N・m)5050

Application examples

1
Workplace

Cylinder Head Valve Guide Hole (FCD)

Cutting tool

Carbide Reamer 6mm×135L

Conventional Chuck

Competitor’s Collet Chuck

SHOWA Chuck

SHOWA Micron Chuck HSKA63-HPC10H-105A

Test result①Though conventional collet chuck required 30min to achive 10micron runout. SHOWA
Micron chuck was able to achieve 3 - 5micron at 8×D with just one clamping.
②As a result, a longer tool life is realized from 50 - 100 holes to 1600 holes.

Workplace

Cylinder Block Oil Jet Hole (FC230)

Cutting tool

Carbide Reamer 9mm×180L

2

Conventional Chuck
SHOWA Chuck

Micron Chuck
M TypeHydraulic Chuck+Straight shank shrink fit extension
SHOWA Micron Chuck HSKA63-HPC10M-254

Test result

Increased cutting tool life from 400 to 1000 holes, thereby reducing cutting tool costs
and tool changing costs

WorkplaceHydraulic Parts Cover（ADC12）

Cutting tool

Carbide Step Reamer 20mm×200L

3

Conventional Chuck
SHOWA Chuck

Competitor’s Milling Chuck
SHOWA Micron Chuck BT40-HPC25-105A

Test result

Measuring Position

SHOWACompetitor

180mm
290mm

0.005
0.017

0.015
0.03

②No more chattering

290mm①Runout Comparison on the M/C

180mm

290mm

4Workplace

Cylinder Head Cubing (ADC)

Cutting toolDiamond Reamer

Conventional Chuck
SHOWA Chuck
Test result

Competitor’S Hydraulic Chuck
SHOWA Micron Chuck HSKA63-HPC25-115AA

Micron Chuck

Hydraulic chuck produced oval holes.Micron chuck produced perfect circular holes.

6