Magnetic Chucks
Magnetic chucks include several types such as electromagnetic chucks,
permanent magnetic chucks and permanent electromagneticchucks, each having particular functional features.
In the machining industry, it has been known since the beginning of the 20th century
to apply magnets to holding workpieces. In particular, recent technologicaldevelopment has expanded the scope of applications of magnetic chucks from only
grinding machines to heavy duty cutting processes by machining centers, lathes,
milling machines, etc. Today the applications have further been expanded to include
metallic mold machining and electric discharge machining. Thus, the magnetic chucks
that meet these high precision machining requirements play a very important role inmany machining fields.
In addition to magnetic chucks, KANETEC offers chucks designed for nonmagnetic
materials to respond to requirements in grinding of various materials. We believe you
will find products in this brochure that meet your diversified needs.

■Types of Chucks by Applications
Machining

Application

Heavy duty
cutting・Material roughmachining

MachineApplicable Chuck (Typical Model)

・Machining
center・Material
cutting

Machining loadGeneralcutting

・GeneralfinishingLight duty
cutting・Finishing(Straightening)

Heavy duty
grinding

・Material
grinding

・GeneralfinishingElectromagnetic: KETZ
Permanent electromagnetic:
EP-Q, EP-D
Permanent electromagnetic(round): EPC-Z
Electromagnetic: ACSHIM KEZF
Permanent magnetic: RMA・Milling
machine・Lathe・Turning
machine・Rotary
grinder・Surface
grinder

Electromagnetic: KESLElectromagnetic: KET
Permanent electromagnetic: EPTElectromagnetic: KETL

・Beltgrinder・Finishing(Straightening) ・Cylindrical

Generalgrinding

Permanentmagnetic:
RMT, RMAW

grinder・PrecisionfinishingPrecision
grinding

Electric
discharge
machining

Nonferrous
machining
Weakmagnetism()

Permanent
magnetic:
RMWH

・Mold
grinder・Moldmachining・Electric
discharge
machine・Grinding/cutting, etc.

・Machines
ingeneral

Permanent
magnetic:
Super thin
type RTH

Nonmagnetic
materials:
Vacuumchuck KVR

01

Electromagnetic: KETN
Electromagnetic (round):
KEC-AS
Permanent electromagnetic(round): EPC-AST
Permanent magnetic: RMA-C

Electromagnetic: KETW
Permanent electromagnetic:
EPTW
Electromagnetic (round):
KEC-AR
Permanent electromagnetic(round): EPC-AR

50

Permanentmagnetic(round):
RMC, RMC-X
RMAW-C

Permanentmagnetic(round):RMCW

Permanent magnetic:
Cemented carbide CMR

100

Nonmagnetic
materials:
PROMELTASYSTEM PRB
150

200

Holding power (□50×t 25, S15C test piece)

250

300
［kgf］

OVERVIEW OF MAGNETIC CHUCKS■Overview and Features of Chucks
Electromagneticchuck●Very efficient since workpieces can be attached/detached by switching operation.
●Easy automation by interlocking the chuck and the machine.
●Easy adjustment of the holding power.
●Easy to make a larger type of the chuck.

Permanentmagneticchuck●Energy-saving type, requiring no power source. No fear of power
failure and capable of holding workpieces for a long time.
●No heat generation and thus no thermal distortion due totemperature rise.

Water-cooledelectromagneticchuck●Constructed to reduce heat generated during power on by water cooling.
●Suitable for high-precision machining and exhibits features ofelectromagnetic chucks.
●Most suitable for dry grinding. (Heat from workpieces themselves isabsorbed also.)

Sine bar chuck

Permanent
electromagneticchuck●Very eﬃcient since workpieces can be attached/detached by switching
operation.
●Energy-saving, since electric power is used momentarily for
attaching/detaching workpieces only.
●High accuracy because of no thermal distortion due to heat generated
during power on.
●No change in the holding power in the event of power failure while theworkpiece is being held.

●Magnetic chuck equipped with a sine bar for high-precision grinding
and inspection.
●Precisely ﬁnished to overall accuracy of 0.005 mm or better.
●Various types are available; electromagnetic, water-cooledelectromagnetic, permanent magnetic and permanent electromagnetic
chucks.

Vacuum chuck●Holds workpieces by action of atmospheric pressure.
●Vacuum chucks nonmagnetic materials.

PROMELTAsystem●Secures workpieces to a dedicated chuck using workpiece ﬁxingagent.
●Secures nonmagnetic materials.

■Types of Electromagnetic Chucks
TypeModelApplication

Applicable MachineWith T-groove

KEZX

Super powerful type

KETZ

Heavy duty cutting
high-speed cutting

Powerful waveform type

KETN

Cutting

Lateral fine pitch type

KESL

Grinding, light duty cutting,belt grinding

Air-up type

KETBGrindingStandard rectangular type

KETGrinding, light duty cutting

Micropitch type

KETW

Thin workpiece grinding

Tilt type

KET-U

Mold grinding

Connecting and tilt type

KET-UT

Large workpieces, angular grinding of cutters

KEC-AR

Ring pole: Grinding

KEC-ASStar pole: Cutting

Grinder, lathe, rotary grinder,
turning machine (face lathe)

KCT/KCT-U

Grinding

Grinder

KCC

Grinding, rotary grinding

Grinder, rotary grinder

Round type
Water-cooled type

Remarks

Machining center
Milling machine
Large planomiller
KEZX
KETZ

Milling and grinding machine,
mass-production saw blade grinder

KETKESL

Grinder

KEC-ARKEC-AS

KCT-UKCC■Types of Permanent Magnetic Chucks
TypeModelApplication

Applicable MachinePowerful type

RMACutting, heavy duty cutting

Milling machine

For small and thinworkpieces

RMAW

Light duty cutting and grindingof small and thin workpieces

Grinder, milling machineStandard type

RMTLight duty grinding and cuttingof thin to thick workpieces

Grinder, electric
discharge machine

Rectangular type,micropitch

RMWH

Fine-pitch grinding of small and Grinder, electricthin workpieces, holding in liquid discharge machine

Tilt type

RMT-U

Mold grindingGrinder

Cutting

LatheLight duty cutting, grinding

Grinder, lathe

Powerful round type

RMA-C

Star-pole round type

RMC-X

Standard round type

RMC

For small and thin workpiece

RMAW-C

Round type, micropitch

RMCW

Universal grinding of thin tothick workpieces

Super thin type

RTH

Light duty grinding andhigh-speed grinding

For cemented carbide

CMR

Grinding of weak magnetic
materials such as cemented carbide

Rectangular type with jet hole RMT-ED
Round type with jet hole

RMC-ED

Rectangular type, micropitch RMWH-ED

Remarks

RMA

RMT

RMWH

RMT-URMC

Improved water tightness,securing workpieces during
electric discharge machining

Grinder

RMC-X

RMCW

RTH
RMWH-ED

Electric discharge machine■Types of Permanent Electromagnetic Chucks
TypePowerful type

Model
EP-Q

Application

Demagnetizing function type EP-D

Heavy duty cutting,general cutting

Rectangular type

EPT

Grinding

Micropitch type

EPTW

Grinding thin workpieces

Tilt type

EPZ-U

Mold grinding

Round type

EPC

Turning, grinding

Remarks

Applicable Machine
Milling machine,machining center
Grinder
Lathe, turning machine

EP-Q

EPC-AST

EPTW

Cylindrical grinder,
rotary grinderEPTEPZ-U2

Magnetic Chucks■An example of holding power <<Electromagnetic chuck>>

Holding Power of Magnetic Chucks（1N≒0.1kgf）

There is no absolute rule for selection of pitches suitable for workpieces. A
general guide, however, is that the best condition for holding is that the thicknessof workpieces is 2 to 4 times the pitch.
To attract a workpiece firmly, it should be placed over the N pole and S pole, andaccordingly, the attractive face of workpieces must at least be 3 times the pitch.

10075
KETZ50● Relation between thickness ofworkpiece and holding power
Test piece 50 × 50 mm, SS400 ground surface
（N）
6000

KETN

25200

3000

KESL

2000

KET600（cm2）

400

KETN

4000

1000

KET・KEC

0KETZ

5000

Holding power

Holding Power and Pitch between Poles

Holding power per unit area

The holding power varies largely depending on the type of magnetic chucks and●Relation between attractive area ofmaterial, thickness and attractive area of workpieces and distribution of mass andworkpiece and holding powersurface roughness of the attractive face of workpieces. The following graphs show
Test piece thickness 25 mm, SS400 ground surface
typical examples; you can refer to them for tendency. Please note, however, that （N/cm2）
150
values differ slightly among chucks. Always locate workpieces in such a mannerthat the holding area is positioned over both the N and S poles.
125

100

Attractive area of test piece

20Thickness of test piece30（mm）■An example of construction of rectangular electromagnetic chuck ■An example of construction of rectangular permanent magnetic chuck
Waterproof layer
Iron core
Coil
Face plate

Separator

Magnetic pole

Separator
Face plateCaseMagnetBody

Base plate
Iron core■An example of holding power <<Permanent magnetic chuck>> ■Relation between material and holding power（1N≒0.1kgf）<<Chucks in general>>●Relation between thickness of workpiece and holding power
Test piece 50 × 50 mm, SS400 ground surface

Test piece 50 × 50 mm, SS400 ground surface

（N）
3000

（N）
600

Max. holding power

Max. holding power

RMA
2500

/LJKWGXW\FXWWLQJ
RMT・RMC

2000
1500

RMWH・RMCW

1000+HDY\GXW\RTH
JULQGLQJ

500
01020500
400

RMWH・RMCWRTH300●Difference in holding power due toattractive surface roughness (%)

00255075100（％）

2550

SS400

SS400

▽▽▽ GSUS430

SS400▽▽S45C

SS400▽

S45C hardened

SS400〜75100（％）

SKH2200

SKH2 hardened

10030（mm）●Difference in holding power due tomaterials (%)

FC400

0

1.0

Thickness of test piece

2.0

Thickness of test piece

3.0（mm）

FC200■An example of holding power <<Permanent electromagnetic chuck>> Selection of grinding fluid（1N≒0.1kgf）

The separator part of the chuck work faces is made of brass, resin, etc. Selectgrinding fluid that does not corrode these materials. For details, please consult
with grinding fluid suppliers.

●Relation between thickness of workpiece and holding power
Test piece 50 × 50 mm, SS400 ground surface

Max. holding power

（N）
3500
3000

Environmentallyfriendly

EP-Q

2500

EP-D

2000

EPT-DWM
1500

EPT-H

1000

※The data shown in an example of holding power is reference datataken from typical models and does not indicate warrantedvalues.
※Use the Facsimile Communication Form (Selection Data) at theend.

EPT5000510152025

Thickness of test piece■Standards
The quality standards of electromagnetic chucks have been established as described in the right-sidetable for dimensional accuracy(flatness/parallelism), holding
power, electrical performance (withstand voltage/insulation resistance/temperature rise limit) and water
resistance including testing methods.

3

These magnetic chucks employ special resin forbonding attractive face structural members,
instead of solder that is normally used, but is anenvironmentally hazardous substance.

30（mm）

Standards of electromagnetic chucks（mm）

Up to 300

Over 300 up to 600

Over 600 up to 900

Over 900)ODWQHVV

0.01

0.015

0.02

0.025

3DUDOOHOLVP

0.02

0.03

0.04

0.05

/HQJWKRUGLDPHWHURIIDFHSODWH

Surface roughness: 6.3S
Mounting face: Not convex.

+ROGLQJSRZHUThe holding power on the chuck face plate must be 98.1 N (10 kgf) or over in average and 49 N (5 kgf) or over in the weakest area.

:LWKVWDQGYROWDJHDielectric breakdown between the charged part and the body is not allowed. (1500 VAC, 1 min.),QVXODWLRQUHVLVWDQFH

The insulation resistance must be 5 ΩM or over. (Measured with 500 V insulation resistance tester)

7HPSHUDWXUHULVH

The temperature rise on the chuck work face must be below 15℃. (Powered on for 3 hours):DWHUUHVLVWDQFH

When a chuck is immersed in water, no water must enter the inside or its insulation performance must not drop.

Note: The standards for the holding power and temperature rise vary depending on models.

OVERVIEW OF MAGNETIC CHUCKS

Permanent electromagnetic chuck for cutting (An example of large size)

Permanent magnetic chuck for electric discharge machine
Vertical 2-face holding permanentelectromagnetic chuck

Permanent electromagnetic chuck for grinding (An example of large size)

Chucks of special specifications not listed in this catalog are also available.

4