MA1408PHG
Version 1.03 (2024.01.05)
Original Instructions

INSTRUCTION MANUALBRT type (BRT06, 08, 10, 12)Standard Chuck

Kitagawa Corporation
77-1,Motomachi,Fuchu -shi,Hiroshima,726 -8610,Japan
TEL +81-(0)847 -40-0526
FAX +81-(0)847-45-8911
Before using this product, be sure to read this manual
carefully to understand how to use it correctly.

Contents
1

2
3

Preface2

1.1 How to Use This Manual2

1.2 Signal Word Definition

3

1.3 Type Designation

3

1.4 Application Purpose of This Product4

1.5 Unacceptable Application Example

4

1.6 Structural Drawing

4

1.7 Product Range

5

1.8 Warranty

5

1.9 Parts List

5

Important Safety Precautions

7

Technical Data

11

3.1 Specifications

11

3.2 Calculation of Operating Condition

13

3.3 Relationship Between Gripping Force and Rotational Speed

17

3.4 Relationship Between Gripping Center Height and Static
Gripping Force/Input Force
Relationship Between Moment of Mass of Top Jaw and Loss17

of Gripping Force
4

Soft Jaw

20

4.1 Installation of Soft Jaw

20

4.2 Stroke mark21

4.3 External Gripping Soft Jaw Forming Procedure

22

4.4 Internal Gripping Soft Jaw Forming Procedure23

4.5 Tnut-Plus

24

5

Additional Machining Allowable Range

26

6

Maintenance and Inspection

27

7

6.1 Periodic Inspection

27

6.2 Grease Supply

27

6.3 Disassembly28

Troubleshooting

29

7.1 Troubleshooting

29

7.2 Contact Information In Case Problem Occurs

30

1For Machine Manufacturers
89Installation

31

8.1 Installation Conceptual Diagram

31

8.2 Back plate

33

8.3 Draw Pipe34

8.4 Disassembly of Draw Nut and Threading35

8.5 Chuck Installation Procedure

35

Others37

9.1 Standard or Directive to Conform

37

9.2 Marking of Product37

9.3 Disposal

38

1. Preface
1.1. How to Use This ManualThis manual provides detailed information on this product so that you can understand its performance andfunctions and use it safely and correctly. Before using this product, be sure to read this manual carefully tounderstand how to use it correctly.

This manual has been prepared for intended use for persons in charge of installation, operation,
inspection, and maintenance of this product. When the beginners use this product, be sure to receive theguidance from skilled persons, sales agents, or us in advance.

Store this manual with care in the specified place at hand, and reread it as necessary for correct use of the
product.

This manual is a part of the product. Do not sell or transfer the product to a third party without attaching
this manual.



Read the section "Important Safety Precautions" at the beginning of this manual especially carefully, whichsummarizes precautions that particularly you should know or follow.



Failure to follow the instructions and warnings in this manual could result in serious human accidents.
Kitagawa shall not be held liable for human accidents, death, damage, or loss that occurred due to a
failure to follow this manual.

This manual does not predict all potential hazards in installation, operation, maintenance, and inspection
under all environmental conditions. Therefore, the matters, unless otherwise mentioned clearly as “can bedone” or “may be done” in this manual, should be considered as “cannot be done” or “must not be done”.

Please contact us or our agents if you have an uncertainty about safety when you try to perform
installation, operation, inspection, or maintenance of the product.



The information and product specifications described in this manual are subject to change without noticefor the purpose of improvement.

21.2. Signal Word Definition
The triangle shown on the left indicates warning. The warning signs are used to alert you topotential safety hazards. To avoid death or injuries that could occur, follow all the instructions
given with the warning signs.
Handling precautions that are considered especially important are classified and indicated as shown below
according to the degree of risk that could result.

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Warning

Failure to follow the safety precautions below could result in death or serious injuries.

CautionFailure to follow the safety precautions below may result in minor or moderate injuries.

NoticeIndicates instructions which, if you do not heed given instructions, could result indamage to the product or shortened service life, or damage to peripheral equipment.

The signs are classified and indicated as follows according to the type of risk.

General warning

Fire warning

Fly-out warning

High temperature warning

Rotating part warning

Instruction

1.3. Type Designation
Ｂ

Ｒ

Ｔ

０

８

Ａ

６

BRT chuck

９

９Ａ
Design No.
Chuck installation shape

Chuck size (inch)

Straight : The chuck installation shapes conform to JIS B
6109-1: 2005 and JIS B 6109-2: 2005.

A2-6 : A6
A2-8 : A8

However, only A2-15 (former standard)

A2-11 : A1

conforms to JIS B 6109: 1963.
Figure 1

A2-5 : A5

A2-15 (Former standard) : C5
Type designation

3

A2-15 : K5

1.4. Application Purpose of This Product
The power chuck is installed on machine tools such as NC lathes and machining centres to fix a workpiece.
The power chuck is equipped with the jaws to fix the workpiece and they are opened and closed by means of arotary cylinder. For any other applications, please contact us.

1.5. Unacceptable Application Example
The power chuck is not designed for the applications mentioned below for example.
To fix an object to be pressed, punched, welded or fused

To use as a tool holderTo suspend or transfer an object

To fix another chuck that grips a workpiece

1.6. Structural Drawing
The power chuck and rotary hydraulic cylinder are respectively installed on both side of the machine spindle
and connected with the draw pipe.
The hydraulic pressure applied to the cylinder is converted to thrust that pulls the draw pipe and operates thewedge plunger backward via the draw pipe. Then the master jaw is operated inwardly by the wedge hook andthe force is transferred to the top jaw.

(Including soft jaw, hard jaw,

Grease nipple
Master jaw

T-nut

and special jaw)

Jaw mounting bolt

Top jaw

Wedge hook

Jaw operation

Draw Pipe(Not included)

Cylinder thrust
Cover
Draw nut
Chuck mounting bolt
Plunger nut

Wedge plunger
Figure 2

Structural drawing

4

Body

1.7. Product RangeThis is the chuck instruction manual.
For the cylinder and other peripheral devices, refer to their respective instruction manuals.

1.8. Warranty
The product is warranted for one year after the date of delivery. However, the following cases will void thewarranty.
When parts other than Kitagawa’s genuine parts are used.

When proper maintenance and inspection such as periodic greasing are not performed.



Other than above, when the product is used in methods not following this manual.

1.9. Parts List
All parts used including consumables shall be genuine parts delivered by Kitagawa.
Kitagawa shall not be held liable for human accidents, death, damage, or loss that occurred due to the use of
non-genuine parts.
Table 1
No.

Parts nameStandard delivery range
QuantityNo.

Parts name

Quantity

1

Body

1

9

Coil spring

1

2

Wedge plunger

1

10

Plate wrench for draw nut *2

1

3

Master jaw

2

11

Chuck mounting bolt

44Soft jaw *1

2

12

Jaw mounting bolt *1

4

5

T-nut *1

2

13

Plunger nut mounting bolt

6/8

6Plunger nut

1

14

Cover mounting bolt

4

7Draw nut

1

15

Steel ball

1

8

Cover

1

16

Grease nipple

2

Table 2
No.

Parts name

Optional parts (Paid item)
QuantityNo.

Parts name

Quantity

17

Back plate1

20

O-ring1

18

Back plate mounting bolt

3/6

21

Tnut-Plus *1

3

19

Cap

1

22

Handle wrench for draw nut *3

1*1 : Consumables*2 : Accessory tool
*3 : This is the same tool that comes with the BBT200 series, the conventional model. It is compatible with theplate wrench for draw nut [10].

5There is also a type to attach※ : Optional parts

the back plate to the spindle first.

Figure 3 Parts

6

2. Important Safety Precautions
This chapter summarizes precautions that particularly you should know or follow.
Please read them before starting to use the product.

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Turn off the main power supply of the machine when installing, inspecting, greasing, or
replacing the chuck.
 The chuck may rotate unexpectedly and entangle your body or clothing.
Do not rotate the spindle with the door open.
Provide an interlock to allow spindle rotation only when the door is closed.
 If the door is not closed, the rotating chuck may entangle your body or clothing or cause theworkpiece to fly out.
Do not turn OFF the hydraulic pump or operate the solenoid valve during spindle rotation.
Before performing workpiece transfer during spindle rotation on an opposed 2-spindle lathe,confirm the machine manufacturer that the operation can be performed safely.
 Operating the solenoid valve during spindle rotation will drop or block the hydraulic pressure,causing the gripping force to drop suddenly and the workpiece to fly out.
The rotational speed and input force must not exceed the limit in operation. (Refer to "3.
Technical Data")
 Excessive rotational speed may cause the workpiece to fly out.
 Excessive input force may damage the chuck, causing the workpiece to fly out.
Only the machine manufacturer or the user is to determine cutting conditions, gripping force,and rotational speed according to test cutting result. Adjust the hydraulic pressure so as toobtain the gripping force necessary for machining, and confirm that the necessary gripping
force is obtained before starting machining.
 Insufficient gripping force may cause the workpiece to fly out.
If you use a top jaw higher or heavier than the standard top jaw, determine the operating
condition according to "3.2. Calculation of Operating Condition" on page 13.
 Using a top jaw under excessive operating conditions may damage the chuck, causing theworkpiece to fly out.
For internal gripping, use the chuck with 1/2 or less of the max. permissible input force forexternal gripping.
 Excessive input force may damage the chuck, causing the workpiece to fly out.
When using fixed jaws instead of one top jaw, the input force must be 1/2 or less of the max.
permissible input force.
 Since the input force that is normally applied to two jaws evenly is concentrated in one jaw, thechuck may be damaged, causing the workpiece to fly out.
The gripping diameter must be equal to or less than the body outside diameter.
 Using the chuck with the gripping diameter exceeding the body outside diameter may damage
the chuck, causing the workpiece to fly out.
When machining a workpiece with a long protrusion, support it with the steady rest or thetailstock.
 If not, the workpiece may turn at the end, causing the workpiece to fly out.

7

Do not grip a workpiece with slope shapes or tapered shapes such as a cast.
 Otherwise, the workpiece may slip, causing it to fly out.
If a workpiece or jig causes an unbalance, reduce the rotational speed or correct the state by
mounting a balance weight. The recommended balance quality is G6.3 or less in JIS B
0905:1992.
 An unbalanced workpiece generates centrifugal force, causing the workpiece to fly out.
 Vibration generated by the unbalance may damage the chuck, causing the workpiece to fly out.
Confirm that the chuck or workpiece does not interfere with the cutter or the turret at a low
rotational speed before starting machining.
 A large impact on the chuck or workpiece by interference may damage the chuck, causing thechuck or workpiece to fly out.
If an impact is given to the machine by interference between the chuck/workpiece and thecutter/turret due to malfunction or program errors, immediately stop rotation. Thenthoroughly check for damage or crack on the parts by disassembling and cleaning them andperform repair or replacement if necessary. (Refer to page 28.)
 The impact may cause damage or crack on the parts. Continuous use of faulty parts may
damage the chuck, causing the workpiece to fly out.
Use the chuck and cylinder that are both manufactured by Kitagawa.
If you must use the chuck together with a cylinder manufactured by another company,
confirm Kitagawa or sales agents that the combination of the chuck and the cylinder is safe.
 Depending on the combination with a particular cylinder, the chuck and the cylinder may bedamaged, causing the workpiece to fly out.
Be sure to tighten the bolts with the specified torque listed in Table 3-1 and Table 3-2.
Use a proper tool that can control torque such as a torque wrench.
Use only the bolts attached to the chuck. Do not use other bolts.
 Rotating the chuck with the jaw mounting bolts loosened may cause the jaws and workpiece to
fly out.
 If insufficient bolts are mounted, bolt length is wrong, or tightening torque is improper, the bolts
may be damaged, causing the chuck and workpiece to fly out.
Table 3-1 Specified torque for hex. socket head cap screw
Thread size

M5

M6

M8

M10

M12

M14

M16

M20

M22

M24

Tightening torque [N・m]

7.5

13

33

73

107

171

250

402

539

666

* Strength classification: M20 or smaller = 12.9, M22 or larger = 10.9
Table 3-2 Specified torque for hex. socket button head screw
Thread size

M3

M4

M5

M6

M8

M10

M12

M16

Tightening torque [N・m]

1.4

3.2

6.4

10.8

26.3

52.1

90.9

224

Prevent your hands and fingers from being caught when gripping a workpiece with the chuck.
(To prevent risks, it is recommended to automate the workpiece attaching/detaching
operation.) Otherwise, your hands and fingers may be crushed or cut off.
If any of the abnormalities shown below suddenly occurs during operation, it may be a sign ofdamage of the chuck.


The workpiece slips.

Chattering occurs.



Machining accuracy has become worse.

Machine vibration has been increased.



Chuck gripping force is reduced.
(Gripping force is not increased even by increasing hydraulic pressure.)8If the status is not improved even after taking the measures described on page 29,
immediately stop using the chuck.
Continuous use of faulty parts may damage the chuck, causing the workpiece to fly out.
If the cylinder combined is to be changed due to such as model change of a rotary hydrauliccylinder, change the hydraulic pressure accordingly so as to obtain proper gripping force.
 Use of the chuck under low hydraulic pressure leads to insufficient gripping force, causing theworkpiece to fly out.
 Use of the chuck under high hydraulic pressure leads to damage of the chuck, causing theworkpiece to fly out.
For machine manufacturers

The draw pipe must have sufficient strength with respect to the operating conditions, notcausing run-out and unbalance. The thread accuracy must be 6H / 6g. Tighten the thread
securely with a sufficient penetration length.
 Insufficient strength of the draw pipe, vibration due to unbalance, and looseness of the thread
may damage the draw pipe. If the draw pipe is broken, the gripping force is lost instantaneously,
causing the workpiece to fly out.
For machine manufacturers
Use a lock valve (check valve) built-in type cylinder. (According to JIS B 6150 : 2015, thecylinder must be provided with equipment such as a check valve so as to maintain thepressure for a certain period of time when the hydraulic pressure to the cylinder is blocked.)
Design the hydraulic circuit so that the solenoid valve holds the gripping port position when
the current is not applied.
Sudden drop or interruption of
hydraulic pressure due to power
failure or hydraulic pump failure
will lose the gripping force
instantaneously, causing theworkpiece to fly out.

Chuck

Chuck

open

close
Lock valve

CylinderSolenoid valve

Figure 4

For machine manufacturers

Use a stroke control sensor built-in type cylinder. (According to JIS B 6150 : 2015, thecylinder must be provided with equipment such as a stroke control sensor so that the powerchuck or the cylinder ensures effective generation of the gripping force.) If the jaw stroke becomes insufficient due to chips accumulating inside the chuck or looseneddraw nut, the chuck may not grip the workpiece, causing the workpiece to fly out.
For machine manufacturers

9Warning

Failure to follow the safety precautions below could result in death or serious injuries.

Perform additional machining of tapped holes and pin holes on the chuck only within theallowable range.(Refer to page 26.)
 Additional machining performed out of the allowable range may damage the chuck, causing theworkpiece to fly out.
 Especially, additional machining to the master jaws and T-nut directly causes fly-out of theworkpiece.
Supply grease every day.
When supplying grease, turn OFF the machine main power and be sure to use the specified
grease. (Refer to page 27.)
 Insufficient greasing or use of grease other than the specified one may drop the gripping force,
causing the workpiece to fly out.
Disassemble and clean the chuck every six months or 100,000 strokes (cast machining: every
two months). (Refer to page 28.)
 Omitting the disassembly and cleaning and use of the chuck with chips and coolant remaining
inside the chuck will lead to insufficient stroke and gripping force drop, causing the workpiece to
fly out.
Remove the eye bolts and wrench from the chuck after use.
 Rotating the chuck without removing the eye bolts and wrench may cause them to fly out.
Use rustproof coolant.
 Otherwise, rust that will be formed inside the chuck may drop the gripping force, causing theworkpiece to fly out.
When stopping the machine for a long time or when storing the chuck without using it for along period, supply grease and rustproof them beforehand.
 Otherwise, rust that will be formed inside the chuck may drop the gripping force, causing theworkpiece to fly out.
Do not wear clothing or accessories such as gloves and necktie which are easy to be caughtin.
 Otherwise, your body or clothing may be entangled.
Do not perform the work after drinking alcohol or taking medicine.
 Impaired judgment or operation mistake may cause serious hazards.

CautionFailure to follow the safety precautions below may result in minor or moderate injuries.

Do not touch machined workpieces with bare hands. (To prevent risks, it is recommended toautomate the workpiece attaching/detaching operation.) Touching workpieces with bare hands may cause a burn because the workpieces may be veryhot.
Remove the workpiece from the chuck when stopping the machine for a long time.
 Failure to do so may lead to drop or interruption of hydraulic pressure or malfunction of thecylinder, causing the workpiece to drop.
When attaching/detaching the chuck to/from the machine, use appropriate lifting devices
such as eye bolts and a floor-operated crane.
 Lifting a heavy chuck by hands will cause a backache.
 Slipping and dropping the chuck from hands may result in a bruise.

10

3. Technical Data
3.1. Specifications
Table 4-1 Specification table
Type

BRT06

BRT08

BRT10

BRT12

mm

12

16

19

23

Jaw stroke (in diameter)

mm

5.5

7.4

8.8

10.6

Max. permissible speed

min-1

6000

5000

4500

3500

Through hole diameter

mm

53

66

81

106

Max. permissible input force

kN

15.3

23.3

32.7

40

Max. static gripping force

kN

39

60

82

104

1.6 (SR1453)

2.2 (SR1566)

2.3 (SR1781)

2.3 (SR2010)

1.5 (SS1453K)

1.8 (SS1666K)

2.2 (SS1881K)

2.1 (SS2110K)

External gripping

Plunger stroke

Max. permissible hydraulic pressure(operating cylinder) *1

MPa
kN

16

29

29.4

44.2

Gripping range

mm

φ20～170

φ28～210

φ38～254

φ54～315

Max. permissible input force

kN

7.7

11.7

16.4

20

Max. static gripping force

kN

19.5

30

41

52

0.9 (SR1453)

1.1 (SR1566)

1.2 (SR1781)

1.2 (SR2010)

0.8 (SS1453K)

1.0 (SS1666K)

1.1 (SS1881K)

1.1 (SS2110K)

kg

12.5

21.7

34.9

56.2

kg・m2

0.05

0.13

0.32

0.78

Standard soft jaw type

SJ06A1T

SJ08A1T

SJ10A1T

SJ12N1T

Tnut-Plus type (option)

TN06PLUS

TN08PLUS

TN10PLUS

TN12PLUS

Internal gripping

Dynamic gripping force at max. speed

Max. permissible hydraulic pressure(operating cylinder) *1

Mass *2
Moment of inertia *3

MPaBalance quality of chuck body *4

JIS B 0905 : 1992

Storage temperature / operating temperature *5-20～+50℃/

G6.3-10～+40℃*1 : The max. permissible hydraulic pressure differs depending on the cylinder used.
Set the hydraulic pressure according to the cylinder type.
*2 : The mass is a value when the standard soft jaws and chuck mounting bolts are included.
*3 : The moment of inertia is obtained by including the standard soft jaws and chuck mounting bolts.
Here, the soft jaws are mounted to the position protruding outward from the master jaws by a half pitch at
the center of the jaw stroke.
*4 : The balance quality of the chuck body is a value when the soft jaws, T-nut, and jaw mounting bolts are notincluded.
*5 : When storing the product, it should be subjected to the antirust treatment and stored in a place free fromwetting, condensation, or freeze.

11The max. static gripping force in the specifications is the value to be obtained under the following conditions.


At the max. permissible input force

Kitagawa's standard soft jaws are used.

The soft jaw mounting bolts are tightened to the specified torque. (Refer to page 8.)

The gripping meter is gripped at the center of the jaw stroke. Here, the soft jaws are attached to theposition where the soft jaw circumference side end face and the chuck circumference are almost aligned.

The gripping force is measured by the Kitagawa's gripping meter, and the height of the gripping position is
as shown in Figure 5. (Also refer to Table 5)

The specified grease is used. (Refer to page 27.)



A variable capacity type pump having a delivery capacity of 20 L/min or more is used as the hydraulicpressure source.
The pressure is set by the regulator of the pump or that separately provided.
Chuck circumference

Pressing force per

Soft jaw circumference end face

one jaw

Kitagawa's
gripping metermax. permissible
input force(Cylinder thrust)𝐻oFigure 5

Gripping force measuring method* The gripping meter indicates the pressing force per one jaw. The gripping force is the total of the pressing
forces of all jaws.

123.2. Calculation of Operating Condition
Table 5

Symbols for calculation and the meanings

SymbolMeaning

𝐻oGripping center height in specifications

𝐻
𝐻T
𝐻max
𝐹g max

𝐹gH

BRT06

BRT08

BRT10

BRT12

mm

19

21

23

27

Gripping center height in operation

mm

-

-

-

-

Top surface height of standard soft jaw

mm

33

39

43

52

mm

60

70

80

90

Gripping part center limit height(recommended value)
Max. static gripping

External gripping

kN

39

60

82

104

force

Internal gripping

kN

19.5

30

41

52

kN

-

-

-

-

Static gripping force withat max.

permissible input force

𝐹g

Static gripping force in operation

kN

-

-

-

-

𝐹gD

Dynamic gripping force in operation

kN

-

-

-

-

𝑄max

Max. permissible input

External gripping

kN

15.3

23.3

32.7

40

force

Internal gripping

kN

7.7

11.7

16.4

20

𝑄

Input force in operation

kN

-

-

-

-

𝑚o

Mass of one standard soft jaw

kg

0.439

0.808

1.229

1.793

𝑚

Mass of one top jaw used

kg

-

-

-

-

𝑟o

Gravity radius of standard soft jaw

mm

45.4

55.5

70.1

98.1

𝑟

Gravity radius of top jaw used

mm

-

-

-

-

𝑧

Number of jaws

2

2

2

2

𝑛max
𝑛
𝐹c max

𝐹c

𝛥𝐹c
𝐴
𝐵

Max. permissible speed

min-1

6000

5000

4500

3500

Rotational speed in operation

min-1

-

-

-

-

kN

36

54

52.6

59.8

kN

-

-

-

-

kN

-

-

-

-

190

349

440

1973

21

24

25

27

Loss of gripping force at max.
permissible speed
Loss of gripping force at rotational speed
during operation
Loss of gripping force of moment ofmass increase
Coefficient specific to each type13

3.2.1. Calculation of Static Gripping Force at Gripping Center Height
The gripping center height is the distance from the mechanical center point of the gripping force acting on
the workpiece to the chuck surface.
When the gripping surfaces of the top jaws contact the workpiece evenly, the mechanical center point of thegripping force is at the center of the gripping surface. If the gripping surfaces contact unevenly or estimationof the gripping center height is difficult, the gripping force should be calculated using the distance from the
top jaw top surface to the chuck surface so as to give priority to safety.
When the gripping center becomes higher, the static gripping force is decreased even if the input force
is the same.



If the gripping center height is higher than, load to be applied to the master jaws, T-nuts, and jaw
mounting bolts will increase. To prevent these parts from being damaged, the input force must be
reduced to suppress the gripping force to a low level.



It is recommended to adjust the gripping center height to beor less.

𝐹gH

𝐹g maxStandard soft𝐻o

Top jaw used

Mechanical center point ofgripping force

𝐻T（If it is unknown whether the𝐻gripping surfaces contact
evenly, calculate the gripping
force using the top jaw top
surface position.）

Figure 6whenis or less

𝐹gH = 𝐹g𝑚𝑎𝑥 ×



when

Gripping center height𝐻o + 𝐴
𝐻+𝐴

is more than𝐹gH = 𝐹g 𝑚𝑎𝑥 ×

𝐻o + 𝐴 𝐻T + 𝐵
×
𝐻+𝐴
𝐻+𝐵

14

3.2.2. Calculation of Loss of Gripping Force due to Centrifugal ForceCentrifugal force is produced on the jaws during chuck rotation. It acts in the direction reducing the gripping
force especially in external gripping. This is called "loss of gripping force due to centrifugal force".
Loss of gripping force due to centrifugal force is proportional to the square of the rotational speed, andthorough consideration is necessary especially for high speed rotation. In addition, a larger mass or gravity
radius of the top jaws will increase loss of gripping force due to centrifugal force.

𝑚

𝑟o

𝑟

𝑚o

Standard soft jaw

Figure 7



Top jaw used

Loss of gripping force due to centrifugal force𝑚 × 𝑟 when 𝑚o × 𝑟o is more than
2×𝜋×𝑛 2𝛥𝐹c = 𝑧 × (𝑚 × 𝑟 − 𝑚o × 𝑟o ) × () × 10−660𝐹c = 𝐹c max ×



𝑛2
+ 𝛥𝐹c
2
𝑛max

𝑚 × 𝑟 when 𝑚o × 𝑟o is or less𝐹c = 𝐹c max ×

𝑛2
2
𝑛max

3.2.3. Determination of Gripping Force
Determinein consideration of gripping force loss due to centrifugal force and necessary operating

conditions such as cutting conditions, workpiece distortion, and strength of the top jaws. However,beor less. The dynamic gripping force during rotation

For external gripping
𝐹gD = 𝐹g − 𝐹cFor internal gripping
𝐹gD = 𝐹g + 𝐹c

（ 𝐹gD ≦ 𝐹gH ）15

is calculated as indicated below.

must3.2.4. Calculation of Input Force for Operation
Calculate the input force required to obtain the necessary gripping force.




when

is or less

𝑄 = 𝑄max ×

𝐹g
𝐹gH

when
𝑄 = 𝑄max ×

is more than𝐹g
𝐻T + 𝐵×
𝐹gH 𝐻 + 𝐵

3.2.5. Calculation of Hydraulic Pressure in Operation
Calculate the hydraulic pressure to be applied to the rotary hydraulic cylinder to obtain the necessary input
force.
The following description is predicated on the use of Kitagawa's SR cylinder or SS-K cylinder. When using
another cylinder, refer to its instruction manual.

𝑃 = (𝑃c max − 0.25) ×𝑄𝑄c max+ 0.25

When the hydraulic pressure in operation is less than 0.5 MPa, the cylinder may not operate or the operation
speed may become extremely slower.
In this case, it is necessary to increase the input force or select the cylinder again.
Table 6-1
SymbolMeaning

SR1453

SR1566

SR1781SR2010External gripping

kN

43.9

45

58.7

71.8

Internal gripping

kN

47.9

49.7

64.3

75.5

Max. permissible hydraulic pressure of cylinder

MPa

4.2

4.0

4.0

4.0

SS1453K

SS1666K

SS1881K

SS2110K𝑄c maxMax. thrust of cylinder𝑃c max

Table 6-2
SymbolCombination with SR cylinder

Combination with SS-K cylinder

Meaning
External gripping

kN

52.1

65

73.1

71

Internal gripping

kN

56.5

70.6

79.5

74.7

Max. permissible hydraulic pressure of cylinder

MPa

4.5

4.5

4.5

3.5

𝑄c maxMax. thrust of cylinder𝑃c max16

3.3. Relationship Between Gripping Force and Rotational Speed
The graphs in Figure 8 indicate the relationship between the gripping force in each moment of mass of the top
jaw and the rotational speed. They can be used for approximate calculation of operating conditions.

Dynamic gripping force [kN]

39

Dynamic gripping force [kN]Standard soft jaw
39.8 kg・mm

40

30
65 kg・mm
20

100 kg・mm
13
10

0

150 kg・mm

40

200 kg・mm
20

0
0

1000

2000

3000

4000

5000

6000

0

1000

2000

3000

Rotary speed [min-1]

Rotary speed [min-1]

Figure 8-1

Figure 8-2

BRT06

100

4000

5000

BRT08

120

80

100

60
250 kg・mm
40

Standard soft jaw
351.8 kg・mm

104

Standard soft jaw
172.4 kg・mm

82

Dynamic gripping force [kN]

Dynamic gripping force [kN]Standard soft jaw
89.7 kg・mm

60

400 kg・mm
27.3

20

0

80
600 kg・mm
60
900 kg・mm
40
34.7
20
0

0

1000

2000

3000

4000 4500

Rotary speed [min-1]

Figure 8-3

0

1000

2000

3000

3500

Rotary speed [min-1]

BRT10

Figure 8-4

BRT12

3.4. Relationship Between Gripping Center Height and Static Gripping Force / Input Force
Relationship Between Moment of Mass of Top Jaw and Loss of Gripping Force
The graphs in Figure 9 indicate the relationship between the gripping center height and the static gripping
force/input force, and the relationship between the moment of mass of the top jaw and the loss of gripping force,
respectively. They can be used for approximate calculation of operating conditions.

17How to read the graphs is explained below taking BRT08 for example.
When the gripping center height is 21 mm and the input force is 23.3 kN, the gripping force is 60 kN.



If the gripping center height exceeds 39 mm, the input force must be reduced. For example, when thegripping center height is 50 mm, the input force is limited to 20 kN or less.



It is recommended to use the chuck with the gripping center height adjusted to 70 mm or less.



According to JIS B 6150 : 2015, the loss of gripping force due to centrifugal force must not exceed 2/3(67%) of the actual static gripping force. Therefore, the permissible loss of gripping force is 40 kN when
the static gripping force is 60 kN.
The loss of gripping force due to centrifugal force is 31 kN when the moment of mass of the top jaw is 89.7



kg・mm and the rotational speed is 5000 min-1.

50

Input

Static gripping force [kN]

Loss of gripping force [kN]

15.3kN

39 40

26

25

23

6000 min-1
205500 min-1
15
10
5

14kN

Limit

12kN

30

10kN
8kN

20

6kN
4kN

10

33

0

0
0

20

40

60

80

0

100

Standard soft jaw
39.8 kg･mm The moment of mass of the top faw 2×m×r [kg･mm]

Figure 9-1

1020Standard 19mm

30

Static gripping force [kN]

Loss of gripping force [kN]Input
23.3kN60

314500 min-1
20

10

0

50

100

150

16kN

40

12kN

30

8kN

20

4kN

10

39
0

200

10

Standard soft jaw
Standard 21mm
89.7 kg･mm The moment of mass of the top jaw 2×m×r [kg・mm]

Figure 9-2

18

BRT08

Limit

20kN

50

0

0

60

BRT06

40

5000 min-1

50

Gripping center height [mm]

70

30

40

20

30

40

50

Gripping center height [mm]

60

70

40

Input
32.7kN

82 80

52.6

Static gripping force [kN]

Loss of gripping force [kN]

90
54.6
50
4500 min-1
4000 min-1

30
20
10

Limit

28kN

70

24kN

60

20kN

50

16kN

40

12kN

30

8kN

20

10
43

0

0
0

100

200

300

0

400

Standard soft jaw
172.4 kg･mm The moment of mass of the top jaw 2×m×r [kg･mm]

Figure 9-3

20Standard 23mm

40

60

Gripping center height [mm]

BRT10

120
104

60

59.8

3500 min-1

Static fripping force [kN]

Loss of gripping force [kN]

69.3

50
3000 min-1

40
30
20
10

Input
40kN

100

0

200

400

600

30kN

80

25kN
60

20kN
15kN

40

10kN
20

52
0

800

Standard soft jaw
351.8 kg･mm The moment of mass of the top jaw 2×m×r [kg･mm]

Figure 9-4

19

Limit

35kN

0

0

80

20

Standard 27mm

BRT12

40

60

80

Gripping center height [mm]

4. Soft Jaw
4.1. Installation of Soft Jaw
The soft jaw mounting positions can be adjusted by loosening the jaw mounting bolts and changing theserration engaging position with the master jaws.

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Use the T-nut in a state where it does not protrude from the master jaw circumference side
end face.
If not, the master jaws and T-nut may be damaged, causing the jaws and workpiece to fly out.



T-nut
T-nut

T-nut must not
protrudefrom

this face.

Master jaw

Correct

Wrong
Figure 10

Do not use soft jaws as follows.

Soft jaws manufactured by other companiesWith serration pitch different from that of master jaw

Soft jaws joined by welding

If serration engagement is faulty, the master jaws may be deformed and the gripping force isreduced, or the soft jaws may be damaged due to insufficient strength, causing the workpiece to
fly out.

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

When replacing the soft jaws, carefully clean fitting parts of the serration and the T-nuts.
Insufficient cleaning will lead to an accuracy failure.

Set the hydraulic pressure according to the shape and cutting conditions of the workpiece.
Clamping a pipe-shaped workpiece with a high gripping force may deform it.

20

4.2. Stroke markA stroke mark to check the jaw stroke position is stamped on the No. 1 jaw part on the body.
When the jaw is at the open end, the base line of the master jaw is aligned with the outer line of the full stroke
range as shown in Figure 11.
The base line moves across the full stroke range when the jaw is opened / closed. However, the base line must
be within the appropriate stroke range when the chuck grips a workpiece.
Full stroke range
Base line

Appropriate stroke range

Stroke markFigure 11

Stroke mark

Table 7
Type

BRT06

BRT08

BRT10

BRT12

Appropriate stroke range

1

2

2.3

2.7
(mm)

DangerFailure to follow the safety precautions below will result in death or serious injuries.

When gripping a workpiece, the master jaw base line must be within the appropriate stroke
range.


Gripping a workpiece near the stroke end may fail due to unevenness of the tolerance at theworkpiece gripping part, causing the workpiece to fly out.

Frequently gripping a workpiece near the stroke end will apply excessive force to the masterjaws and lead to damage of the chuck, causing the workpiece to fly out.

Before starting work, open and close the jaws without gripping a workpiece and confirm thatthe master jaw base line moves within the full stroke range.


If the jaw stroke becomes insufficient due to chips accumulating inside the chuck or looseneddraw nut, the chuck may not grip the workpiece, causing the workpiece to fly out.

21

4.3. External Gripping Soft Jaw Forming Procedure①

Preparation of disc for finish turning of top jaw

The disc for finish turning of top jaw must have a thickness not to be
distorted with the surface roughness of about 25 s.
It is convenient to prepare several types of discs with different
outside diameters so as to use them properly according to thedimension of the forming part.



It is convenient to cut threads at the center in order to guide thedisc using a bolt when gripping the disc.

②

Machining of disc gripping part

Stroke the jaws to minimum inner diameter side.
Next, machine D1. D1 must be the dimension that can grip the discnear the center of the jaw stroke.
𝐷1 = 𝑑 −③

jaw stroke(in diameter)
2

Gripping of disc

Grip the disc at the D1 part.


Grip the disc while pressing against the chuck front face toprevent it from tilting. Stabilize the disc by gripping it several
times.

Confirm that the master jaw base line is within the appropriate
stroke range when the disc is gripped. (Refer to page 21.)④

Forming

Machine D2 with the disc gripped.
D2 must be the same as the workpiece diameter (approx. H7) and thesurface roughness must be 6.3 s or less.


Set the hydraulic pressure during forming to equal to or slightly
higher than that during machining a workpiece.



If the disc becomes deformed, reduce the hydraulic pressure orchange the disc shape to the one that is hardly deformed.

⑤

Test cutting

Remove the disc and grip a workpiece.


Confirm that the master jaw base line is within the appropriate
stroke range when the workpiece is gripped. (Refer to page 21.)Perform test cutting to confirm that the desired machining
accuracy is obtained and no slip occurs.

Grip the workpiece so that it is brought into contact with thegripping surface A and B.

22

4.4. Internal Gripping Soft Jaw Forming Procedure①

Preparation of ring for finish turning of top jaw

The ring for finish turning of top jaw must have a thickness not to be
distorted with the surface roughness of about 25 s.
It is convenient to prepare several types of rings with different
inside diameters so as to use them properly according to thedimension of the forming part.

②

Machining of ring gripping part

Stroke the jaws to maximum outer diameter side.
Next, machine D1. D1 must be the dimension that can grip the discnear the center of the jaw stroke.
𝐷1 = 𝑑 +③

jaw stroke
2

Gripping of ring

Grip the ring at the D1 part.


Grip the ring while pressing against the jaws to prevent it fromtilting. Stabilize the ring by gripping it several times.

Confirm that the master jaw base line is within the appropriate
stroke range when the ring is gripped. (Refer to page 21.)④

Forming

Machine D2 with the ring gripped.
D2 must be the same as the workpiece diameter (approx. H7) and thesurface roughness must be 6.3 s or less.


Set the hydraulic pressure during forming to equal to or slightly
higher than that during machining a workpiece. For internal
gripping, use the chuck with 1/2 or less of the max. permissible
input force for external gripping.



If the ring becomes deformed, reduce the hydraulic pressure orchange the ring shape to the one that is hardly deformed.

⑤

Test cutting

Remove the ring and grip a workpiece.


Confirm that the master jaw base line is within the appropriate
stroke range when the workpiece is gripped. (Refer to page 21.)Perform test cutting to confirm that the desired machining
accuracy is obtained and no slip occurs.

Grip the workpiece so that it is brought into contact with thegripping surface A and B.

23

BRT chuck（two jaws chuck） and BR chuck（three jaws chuck） are different that recommendable forming
procedure.
(Refer to “Procedure ②" of " 4.3.External Gripping Soft Jaw Forming Procedure " and " 4.4.Internal
Gripping Soft Jaw Forming Procedure ")When grip the round workpiece by BRT chuck, it can be used with more stable gripping accuracy byfollow the procedure above.

4.5. Tnut-Plus
A Tnut-Plus as shown in Figure 12-1 is provided for BRT chucks as an option.
Soft jaws formed using the Tnut-Plus can maintain the gripping accuracy equivalent to just-formed soft jaws
even after they are removed from the chuck once, because they can be reinstalled in the same positions.


For corresponding Tnut-Plus types, refer to Table 4-1.



To maintain the installation repeatability of the Tnut-Plus, when insert the Tnut-Plus and the soft jaws into
the master jaws, and also tightening the mounting bolts, place the master jaws on top. (See Figure 12-2)

To maintain the installation repeatability of the Tnut-Plus for a long period of time, always tighten the jaw
mounting bolts from the chuck outside diameter side ① with the specified torque. (See Figure 12-3)

The Tnut-Plus is elastically deformed when the bolts are tightened. Therefore, the resistance you feel
when tightening the bolts is different from ordinary T-nuts, it is normal.



If the Tnut-Plus is used for a long period of time, the soft jaws may be fixed and become hard to be
removed. In this case, remove them by tapping with a plastic hammer. Apply CHUCK GREASE PRO to
the side of the T-nut to stop it becoming fixed.

The gripping accuracy may be deteriorated due to aging such as fatigue of the workpiece gripping surface.
In such a case, re-form the soft jaws.

Chuck outside diameter side

Chamfer
Chuck inside diameter side
Figure 12-1

Tnut-Plus

Figure 12-2

24

Inserting Tnut-Plus and soft jaw into master jaw

① Tighten first.
② Tighten next.

Figure 12-3 Tightening order of the jaw mounting bolts

Warning

Failure to follow the safety precautions below could result in death or serious injuries.

Mount the Tnut-Plus with the chamfer side facing the chuck inside diameter side. (See Figure12-1)
If it is mounted in the opposite direction, seizure may occur due to significant deformation of themaster jaws. As a result, the gripping force will be reduced, causing the workpiece to fly out.
Do not use the Tnut-Plus on a chuck that does not correspond to it.
(The T-slot shapes of such chucks do not match the Tnut-Plus, so the Tnut-Plus cannot bemounted physically. Do not use the Tnut-Plus forcedly on such chucks by additionallymachining them.)
If the Tnut-Plus is used on such chucks, seizure may occur due to significant deformation of themaster jaws. As a result, the gripping force will be reduced, causing the workpiece to fly out.
Additional machining of the T-nut and master jaws may damage them, causing the workpiece to

fly out.
Do not use soft jaws manufactured by other companies.
If soft jaws manufactured by other companies are used, seizure may occur due to significant



deformation of the master jaws. As a result, the gripping force will be reduced, causing theworkpiece to fly out.
Using soft jaws manufactured by other companies may damage the T-nut, causing theworkpiece to fly out.

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

Do not use soft jaws manufactured by other companies.
When mounting already-formed soft jaws again, use the same T-nut used when the soft jaws wereformed, match the jaw No. of the soft jaws and master jaws, and mount the soft jaws in the sameserration position. Also, carefully clean fitting parts of the serration and the T-nuts.


Failure to follow the above precautions may lead to poor accuracy.

25

5. Additional Machining Allowable Range
When mounting a locator or jig on the body surface, add tapped holes and pin holes within the additional
machining allowable range shown by the oblique line parts in Figure 13.

Figure 13

Additional machining allowable range
Table 8

Type

BRT06

BRT08

BRT10

BRT12

A

30

33

36

42

B

54.5

69

79.5

94.5

C (max)

25

25

25

30

R

5

7.5

7.5

11.5
(mm)

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Provide measures to prevent fly-out by centrifugal force (such as dowel pins) for the locator
or jig. In addition, mount the locator or jig with enough bolts with sufficient strength.
Otherwise, the locator or jig may fly out due to centrifugal force.

26

6. Maintenance and Inspection
6.1. Periodic Inspection
Table 9Periodic inspection

Interval

ContentsSupply grease. When using high speed rotation or a large quantityof water soluble coolant, shorten the greasing interval according tothe operating conditions.

Every day

Before starting work, open and close the jaws without gripping aworkpiece and confirm that the master jaw base line moves within
the full stroke range. (Refer to page 21.)

Every 3 months
Every 6 months or 100,000 strokes(Cast machining: every 2 months)

Upon completion of the work, clean the chuck using an air gun.

Check the bolts of each part for looseness.

Disassemble and clean the chuck.(Refer to page 28.)

6.2. Grease Supply
6.2.1. Specified grease
Table 10
Type

Specified grease

Specified grease
Grease nipple

BRT06
BRT08
BRT10

Grease amount per one point [g]4

CHUCK GREASE PRO

JIS B 1575 : 2000

6

type 1 (M6×0.75)

10

BRT12

12

6.2.2. Greasing Procedure①

Open the jaws, and be sure to turn OFF the main power of the machine before starting the work.

②

Supply the amount of grease shown in Table 10 from the grease nipple of each master jaw using agrease gun.

③

After supplying the grease, open and close the jaws several times without gripping the workpiece.

6.2.3. Safety Information on Grease and Antirust Oil
Applicable rangeSpecified greaseAntirust agent applied to the product at the delivery

For the grease other than the specified one and antirust oil prepared by the customer, refer to the safety data
sheet (SDS) prepared for respective oils.

27

Table 11 First-aid treatment
In case of much aspiration, go to a place where there is fresh air, and cover yourAspirationbody with a blanket to keep your body warm. Consult a doctor if necessary.
Wipe off the oil, and wash your skin with water and soap.

Sticking to your skin

If you feel itchy or you get inflamed, consult a doctor immediately.

Entering your eye

Wash your eye with fresh water for at least 15 minutes, and then consult a doctor.

Accidental drinking

Consult a doctor immediately without vomiting forcibly.

6.3. Disassembly
Read the following disassembling procedure referring to page 5 and 6.
①

Before start of work, be sure to turn off the main power of the machine.

②

Loosen the jaw mounting bolts [12] and remove the soft jaws [4] and T-nuts [5].

③Loosen the cover mounting bolts [14] and remove the cover [8].

④Loosen the chuck mounting bolts [11] and rotate the draw nut [7] using the draw nut plate wrench [10].
Then, remove the chuck from the spindle.

⑤

Remove the wedge plunger [2] toward the rear of the chuck.

⑥

Remove the master jaws [3] toward the inner circumference of the chuck.



Reassemble the product through reverse procedure of disassembly while applying the specified greasesufficiently.

When reinstalling the chuck to the machine, refer to "8.5 Chuck Installation Procedure".

After reassembly, it is recommended to confirm that the specified gripping force is obtained according to
the procedure on page 12.

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Clean the disassembled parts with kerosene, carefully check them for damage, wear, crack, orseizure, and repair or replace them if necessary.
Continuous use of faulty parts may damage the chuck, causing the workpiece to fly out.

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

Reassemble the parts with the jaw numbers marked on the body, wedge plunger, and master jaws
matched respectively.
Also, do not hit the parts each other or give a shock to them. Be especially careful not to hit the bodywhen installing the master jaw.
Failure to observe the precautions may result in accuracy failure.

28

7. Troubleshooting
7.1. Troubleshooting
If a failure is suspected, check the contents in Table 12 again and take necessary measures.

Table 12

Problem

Cause
Parts are damaged

Jaws donot move

Troubleshooting

Slideways get seized

Cylinder does not operateCountermeasure
Disassemble and clean the chuck. Replace damaged parts.
(Refer to page 28.)
Disassemble and clean the chuck. Correct the seized partwith an oilstone or replace the part.

(Refer to page 28.)

Check the piping and electric system, and if normal, repair or
replace the cylinder.

Stroke is

Chips accumulate inside

Disassemble and clean the chuck. (Refer to page 28.)

insufficient

Draw pipe loosened

Remove the draw pipe from the cylinder and retighten it.
Confirm that the master jaw base line is within the

Jaw stroke insufficientappropriate stroke range when a workpiece is gripped.
(Refer to page 21.)Lack of gripping force
The formed diameter of the top
jaw does not match theWorkpiece
slips

workpiece diameter
Excessive cutting force
Lack of grease
Excessive rotational speed

Confirm that the hydraulic pressure is appropriate.
Re-form the jaw according to the correct forming method.
(Refer to "4. Soft Jaw")
Calculate cutting force and check that it is appropriate for thechuck and machine specifications.
Supply grease. (Refer to page 27.)
Slow down the rotational speed to obtain required gripping
force.

Swing due to misalignment of
the bar feeder, steady rest,

Thoroughly conduct alignment to eliminate swing.

tailstock, etc.
Run-out of chuck circumferenceis large

Accuracy
failureAdjust the run-out to 0.020 mm T.I.R. or less.

Dust accumulates in serration

Remove the top jaws and thoroughly clean the serration

parts of master jaw and top jaw

parts.

Jaw mounting bolts are not

Tighten the jaw mounting bolts with the specified torque.

sufficiently tightened(Refer to page 8.)

Top jaw forming method isimproperConfirm that the disc for finish turning of top jaw is parallel tothe chuck end face and it is not deformed by the gripping
force.

29

Due to excessive top jaw height,
top jaws are deformed and jaw
mounting bolts are extended

Lower the top jaw height. Adjust the top jaws so that thegripping surfaces contact the workpiece evenly.

Excessive gripping force

Reduce the gripping force to the extent that machining candeforms workpiece.

be executed to prevent deformation.

7.1.1. Aging of markings due to use
The type and serial numbers marked on the surface of the body may become difficult to see due toprolonged exposure to chips. In such a case, please check the URLs marked on the outer circumferenceof the body, as they also contain information on the type and serial numbers.
Also, the logo plate (blue K mark) is strongly adhered to the body with adhesive, but for the same reason,
it may be scratched or peeled off. If it should peel off, it will not affect performance or safety. This is not a
malfunction, so please use the product with peace of mind.

DangerFailure to follow the safety precautions below will result in death or serious injuries.

In case that the chuck failed to operate due to a seizure or breakage, remove the chuck fromthe machine following the disassembly procedure on page 28. When the top jaws and covers
cannot be removed due to a blockage of workpiece, do not disassemble forcibly but pleasecontact us or our agent.
Forcible disassembly could cause serious human accidents.

The chuck must be repaired only by skilled persons who have received the training course.


Repair by unskilled persons or persons other than us or our agents could cause serious humanaccidents.

7.2. Contact Information In Case Problem Occurs
Please get in touch with our sales agent from which you purchased the chuck or our office of the address givenon the back cover when the chuck fails.

30

For Machine Manufacturers
The sections starting from this page provide explanations for machine manufacturers (who mount the chuck on
machines).
Not only machine manufacturers but also persons who attach/detach the chuck are to read and thoroughly
understand the contents so as to perform safety work.

8. Installation
8.1. Installation Conceptual Diagram

Rotaryhydraulic

Draw pipe

Cylinder adaptor

ChuckcylinderNC latheBack plate
Rear cover

Cylinder lockHydraulic drain hose
Coolant drain hose

SolenoidHydraulic hosevalve

In-line filter

Hydraulic unit

Pump

Tank
Return drain overtank oil surface.

Figure 14

Installation conceptual diagram

31

Danger

Failure to follow the safety precautions below will result in death or serious injuries.

Confirm that the cylinder does not cause pressure drop during machining beforehand when
operating other actuators together with the cylinder using the same hydraulic source.
Reduction of hydraulic pressure will reduce the gripping force, causing the workpiece to fly out.

Provide the drain hose so that drain flows smoothly without stagnation.
The drain must be returned over the oil surface in the hydraulic unit to prevent back pressure.
If drain does not flow smoothly, the cylinder may cause oil leakage, resulting in fire.



For the cylinder and other peripheral devices, follow their respective instruction manuals.
If not, serious human accidents may occur.

Warning

Failure to follow the safety precautions below could result in death or serious injuries.

Eliminate dust in the hydraulic circuit completely. In addition, incorporate an in-line filter.
If foreign substances enter the cylinder, the rotary valve may get seized and the cylinder mayrotate while tearing the hose. Moreover, the hydraulic pressure may be blocked, causing theworkpiece to fly out.
Use a flexible hose to prevent bending stress and tension from being applied to the cylinder.
If the cylinder is rotated with an external force applied to it, the cylinder rotary valve may getseized and the cylinder may rotate while tearing the hose. Moreover, the hydraulic pressure may
be blocked, causing the workpiece to fly out.

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

Especially when using a large hydraulic unit, insert a throttling valve in the pressure supply line torestrict surge pressure.
An excessive surge will shorten the chuck service life.

Use a hydraulic hose with the inside diameter as large as possible and with a piping length as short
as possible.


If the inner diameter is too small or the piping length is too long, the jaw opening/closing speed
may become slow.

Provide the drain hose with a slight flow gradient to avoid any air pocket.


If air is mixed in drain, noise caused by the hydraulic unit may increase or the service life of thehydraulic unit may be shorten.

32

8.2. Back platePrepare a back plate corresponding to the spindle end shape and chuck mounting dimensions.
The chuck mounting dimensions conform to JIS B 6109-2: 2005.

Back plate
Figure 15 Mounting dimensions
Table 13
Type

BRT06

BRT08

BRT10

BRT12

A (H6)

140

170

220

300

B

104.8

133.4

171.1

235

C (max)

82

104

137

155

D

4×M10

4×M12

4×M16

4×M20

E

16

17

22

29

F

5

5

5

6
(mm)

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

The end face run-out and fitting diameter run-out of the back plate must be 0.005 mm T.I.R. or less,respectively. (It is also allowed to mount the back plate on the machine and finish the end face andfitting diameter in this state.)

Excessive back plate run-out may result in accuracy failure.

Dimension C must be equal to or less than the value in Table 13 so that the plunger stroke isrestricted by the back plate.


If the plunger stroke is not restricted, the master jaws may interfere with the cover and bedamaged when the chuck is combined with a cylinder having a stroke longer than the chuckspecifications.

33

8.3. Draw Pipe
Determine the draw pipe length L according to the distance X between the chuck mounting face and cylinder
mounting face. Whether sufficient strength is obtained with respect to the operating conditions must be judged
by the designer of the draw pipe. The dimensions provided in this manual do not guarantee that the draw pipe
will not be damaged under every condition.

Figure 16

Draw pipe
Back plate

Cylinder adaptor

Figure 17

Distance between chuck mounting face and cylinder mounting face

Table 14Type

CylinderSR1453

BRT06

SS1453K
SR1566

BRT08

SS1666K
SR1781

BRT10

SS1881K
SR2010BRT12SS2110K

Draw pipe dimensions

A

B

C

D (f7)E (min)F (max)

L

M60×2

30

20

55

3.5

M60×2

X+36

M75×2

35

25

70

4.5

M75×2

X+44

M90×2

35

25

85

4.5

M90×2

X+41

M115×2

35

30

110

4.5

M115×2

X+40(mm)

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

Do not connect Cylinder and Chuck by connecting multiple draw pipes.


Failure to follow the above precautions may lead to poor accuracy.

34

8.4. Disassembly of Draw Nut and Threading
Read the following procedure referring to page 5 and 6.
①

Loosen the plunger mounting bolts [13] and remove the plunger nut [6] and draw nut [7].
At this time, be careful not to lose the steel ball [15] and coil spring [9].

②

Cut threads in the draw nut [7] corresponding to the draw pipe thread diameter.

③

Assemble the draw nut [7] in the plunger nut [6], and tighten the plunger nut mounting bolts [13].

DangerFailure to follow the safety precautions below will result in death or serious injuries.

Do not cut threads exceeding the dimension F in Table 14 in the draw nut.
The thread accuracy must be 6H / 6g.
If not, the draw nut is damaged due to its insufficient strength and the gripping force is lost
instantaneously, causing the workpiece to fly out.

8.5. Chuck Installation Procedure
For the cylinder mounting procedure, also read the instruction manual of the cylinder.
①

Before start of work, be sure to turn off the main power of the machine.

②

Apply adhesive to the thread part of the draw pipe and screw the draw pipe in the cylinder piston rod.
For the tightening torque to be applied at this time, refer to “2.Important Safety Precautions” on the
instruction manual of the cylinder.

③

Install the cylinder on the spindle.

④

Check the run-out of the cylinder. If normal, connect the hydraulic hose and the drain hose.

⑤Turn on the machine power, and operate the cylinder several times at 0.5 MPa. If it is normal, move thepiston to the forward end and turn off the machine main power.

⑥

Remove the soft jaws and cover of the chuck.

⑦

Insert the draw nut plate wrench into the chuck center hole as shown in figure 18, and connect the draw
nut to the draw pipe while rotating the draw nut. If it cannot be screwed in smoothly, do not screw forcibly
and check the thread for inclination.

⑧

Rotate the draw nut until the chuck is completely fitted to the spindle installation surface.

⑨

Tighten the chuck mounting bolts evenly with the specified torque. (See “2.Important Safety Precautions”)
The chuck circumference run-out must be 0.020 mm T.I.R or less. When performing centering adjustment,
tap the body side face with a plastic hammer.

⑩

Rotate the draw nut until the master jaw base line is aligned with the outer line of the stroke mark.(Refer topage 21.)
A click stop (locking mechanism) is provided for the draw nut. Finish the adjustment at a position where
you feel it click.

⑪

Operate the cylinder at 0.5 MPa and confirm that the master jaw base line moves within the full stroke
range. (Refer to page 21.)35

⑫

If the chuck or cylinder is replaced from another type, calculate and change the hydraulic pressure toobtain the same gripping force as the previous chuck. (Refer to “3.2. Calculation of Operating Condition”.)

Plate wrench for draw nut

Insert the plate wrench into
the notch and turn the draw
nut.

Figure 18

Warning

Failure to follow the safety precautions below could result in death or serious injuries.

If the chuck or cylinder is replaced from another type, calculate and change the hydraulicpressure to obtain the same gripping force as the previous chuck. (Refer to “3.2. Calculationof Operating Condition”.)Insufficient gripping force may cause the workpiece to fly out.

Especially, when replacing from the BBT200 series, it is necessary to increase the oil pressure
to obtain the same gripping force as before.

NoticeIndicates instructions which, if you do not heed given instructions, could result in damage
to the product or shortened service life, or damage to peripheral equipment.

Tighten the chuck mounting bolts evenly with the specified torque. (Refer to page 8.)

If the tightening torque is insufficient, will increase the gap between body and master jaw. Failure
to follow the above precautions may lead to poor accuracy and will shorten the chuck service
life.

36

9. Others
9.1. Standard or Directive to Conform
This product conforms to the following EN standards and EU directive:

Machinery Directive:2006/42/EC Annex I

EN ISO 12100:2010



EN1550:1997+A1:2008

9.2. Marking of Product
Logotype of manufacturer

Jaw No.
F MAX : Max. permissible input force

Name and address of

ΣS MAX : Max. static gripping force

manufacturer
Jaw No.

N MAX : Max. permissible speed
MASS : Mass
Product type

Top jaw type
Logotype of
manufacturer

Type
Serial No.

Stroke markProduct web site URL and 2D code

Country of origin

Figure 19

Marking

The mass stamped on the chuck is the value when the standard back plate is included.

Table 15
Type
Back plate
Spindle end shape
Stamp

BRT06

BRT08

BRT10

BRT12

A2-5

A2-6

A2-6

A2-8

13.5 kg

23.5 kg

40kg

69.3kg

37

Danger

Failure to follow the safety precautions below will result in death or serious injuries.

Markings are standard specifications. Since specifications may be limited due tospecification changes or modifications, refer to the delivery specifications, if available. If
there are no delivery specifications, such as for changes to the jaws by the customer,
determine the operating condition according to "3.2. Calculation of Operating Condition".



If the mass of the jaws is large, the centrifugal force will increase and the gripping force will
decrease, may cause the workpiece to fly out.
Excessive rotational speed may cause the workpiece to fly out.



Excessive input force may damage the chuck, causing the workpiece to fly out.



9.3. Disposal
Dispose of this unit in accordance with the laws and regulations of your country.

38

YY3037PKY2DECLARATION OF INCORPORATION
of partly completed machinery
Copy of original
We hereby declare that the following our product conform with the essential health andsafety requirements of the EC Machinery Directive so that the product is to beincorporated into end-machinery. The product must not be put into service until
end-machinery has been declared in conformity with the provisions of the EC Machinery
Directive 2006/42/EC Annex II part 1.A.
We also declare that the specific technical documentation for this partly completed
machinery was drawn up according to the EC Machinery Directive 2006/42/EC Annex
VII part B.
Product: Standard chuck

Model: BRT series

Serial number: See original declaration

Manufacturer: Kitagawa Corporation
77-1, Motomachi, Fuchu-shi,
Hiroshima 726-8610, Japan

Authorized compiler
in the community: Peter Soetebier / Prokurist
Kitagawa Europe GmbH
Borsigstr.3 D-40880 Ratingen, GERMANY(Models BRT06, BRT08, BRT10, BRT12)

The essential health and safety requirements in accordance with the EC
Machinery Directive 2006/42/EC Annex I were applied and fulfilled:
1.1.2, 1.1.3, 1.1.5, 1.1.6, 1.3.1, 1.3.2, 1.3.4, 1.5.4, 1.5.8, 1.5.9, 1.5.13, 1.6.1, 1.7.1,
1.7.2, 1.7.3, 1.7.4, 1.7.4.1, 1.7.4.2
The following harmonized standards were applied:
EN ISO 12100:2010, EN 1550:1997+A1: 2008
Signature:

See original declaration

Place / Date:

See original declaration

Name / Title:

Tamio Nishimiya /Deputy General Manager
Technical department
Kitagawa Global hand Company

Being the responsible person appointed and employed the manufacturer.

YY3815PKY

UK DECLARATION OF INCORPORATION
of partly completed machinery
Copy of original
We hereby declare that the following our product conform with the essential health andsafety requirements of the Supply of Machinery (Safety) Regulations 2008 so that the
product is to be incorporated into end-machinery. The product must not be put into
service until end-machinery has been declared in conformity with the provisions of the
Supply of Machinery (Safety) Regulations 2008 Annex II part 1.A.
We also declare that the specific technical documentation for this partly completed
machinery was drawn up according to the Supply of Machinery (Safety) Regulations
2008 Annex VII part B.
Product: Standard chuck

Model: BRT series(Models BRT06, BRT08, BRT10, BRT12)

Serial number: See original declaration

Manufacturer: Kitagawa Corporation
77-1, Motomachi, Fuchu-shi,
Hiroshima 726-8610, Japan

Authorized complierin the community: Mark Jones / Financial Director
UNIT 1 THE HEADLANS, DOWNTON,SALISBURY, WILTSHIRE, SP5 3JJ, UNITED
KINGDOM

The essential health and safety requirements in accordance with the Supply of
Machinery (Safety) Regulations 2008 Annex I were applied and fulfilled:
1.1.2, 1.1.3, 1.1.5, 1.1.6, 1.3.1, 1.3.2, 1.3.4, 1.5.4, 1.5.8, 1.5.9, 1.5.13, 1.6.1, 1.7.1,
1.7.2, 1.7.3, 1.7.4, 1.7.4.1, 1.7.4.2
The following harmonized standards were applied:
EN ISO 12100:2010, EN 1550:1997+A1: 2008
Signature:

See original declaration

Place / Date:

See original declaration

Name / Title:

Tamio Nishimiya /Deputy General Manager
Technical department
Kitagawa Global hand Company

Being the responsible person appointed and employed the manufacturer.

https://www.kiw.co.jp
https://www.kitagawa.com

Kitagawa Corporation

Kitagawa Global hand Company

77-1,Motomachi,Fuchu-shi,Hiroshima,726-8610,Japan

Tel. +81-847-40-0561

Fax. +81-847-45-8911

 JAPAN DOMESTICTokyo office1-405-1,Kita-ku,Yosino-cho,Saitama-shi,Saitama,331-9634,JAPAN
Tel. +81-48-667-3469
Fax. +81-48-663-4678

Sendai office

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Tel. +81-22-232-6732
Fax. +81-22-232-6739

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Tel. +81-52-363-0371
Fax. +81-52-362-0690

Osaka office

3-2-9,Kitakagaya,Suminoe-ku,Osaka-shi,Osaka,559-0011,Japan
Tel. +81-6-6685-9065
Fax. +81-6-6684-2025

Hiroshima office77-1,Motomachi,Fuchu-shi,Hiroshima,726-8610,Japan
Tel. +81-847-40-0541
Fax. +81-847-46-1721

Kyushu office

7-6-39,Itazuke,Hakata-ku,Fukuoka-shi,Fukuoka,812-0888,Japan
Tel. +81-92-501-2102
Fax. +81-92-501-2103

Overseas office77-1,Motomachi,Fuchu-shi,Hiroshima,726-8610,Japan
Tel. +81-847-40-0526
Fax. +81-847-45-8911

 OVERSEASKITAGAWA-NORTHTECH INC.
America Contact

https://www.kitagawa-usa.com

301 E. Commerce Dr,Schaumburg,IL. 60173 USA
Tel. +1 847-310-8787
Fax. +1 847-310-9484

KITAGAWA MEXICO S.A. DE C.V
Circuito Progreso No. 102, Parque Industrial Logistica Automotriz, Aguascalientes, Ags., C.P.20340
Tel. +52 449-917-8825

Fax. +52 449-971-1966

KITAGAWA EUROPE LTD.

https://www.kitagawa.global/en
Unit 1 The Headlands,Downton,Salisbury,Wiltshire SP5 3JJ,United Kingdom
Tel. +44 1725-514000
Fax. +44 1725-514001

KITAGAWA EUROPE GmbHhttps://www.kitagawa.global/deBorsigstrasse 3,40880,Ratingen Germany
Tel. +49 2102-123-78-00
Fax. +49 2102-123-78-69

KITAGAWA EUROPE GmbH Poland Office
Europe Contact

https://www.kitagawa.global/pl44-240 Zory,ul. Niepodleglosci 3 Poland
Tel. +48 607-39-8855

KITAGAWA EUROPE GmbH Czech Officehttps://www.kitagawa.global/cz

Purkynova 125,612 00 Brno,Czech RepublicTel. +420 603-856-122
Fax. +420 549-273-246

KITAGAWA EUROPE GmbH Romania Officehttps://www.kitagawa.global/roStrada Heliului 15,Bucharest 1,013991,Romania
Tel. +40 727-770-329

KITAGAWA EUROPE GmbH Hungary Officehttps://www.kitagawa.global/hu

Dery T.u.5,H-9024 Gyor,Hungary
Tel. +36 30-510-3550

KITAGAWA INDIA PVT LTD.

https://www.kitagawa.global/in
Plot No 42, 2nd Phase Jigani Industrial Area, Jigani, Bangalore – 560105, Karnataka, India
Tel. +91-80-2976-5200
Fax. +91-80-2976-5205

KITAGAWA TRADING (THAILAND) CO., LTD.

https://www.smri.asia/jp/kitagawa/9th FL,Home Place Office Building,283/43 Sukhumvit 55Rd. (Thonglor 13),Klongton -Nua,Wattana,Bangkok 10110,Thailand
Tel. +66 2-712-7479
Fax. +66 2-712-7481

Kitagawa Corporation(Shanghai)
Asia Contact

https://www.kitagawa.com.cn
Room308 3F Building B. Far East International Plaza,No.317 Xian Xia Road,Chang Ning,Shanghai,200051,China
Tel. +86 21-6295-5772
Fax. +86 21-6295-5792

Kitagawa Corporation(Shanghai) Guangzhou OfficeB07,25/F,West Tower,Yangcheng International Trading Centre,No.122 East Tiyu Road,Tianhe District,Guangzhou,China
Tel.+86 20-2885-5276

DEAMARK LIMITED

https://www.deamark.com.tw

No. 6,Lane 5,Lin Sen North Road,Taipei,Taiwan
Tel. +886 2-2393-1221
Fax. +886 2-2395-1231

KITAGAWA KOREA AGENT CO., LTD.

http://www.kitagawa.co.kr
803 Ho,B-Dong,Woolim Lion's Valley,371-28 Gasan-Dong,Gumcheon-Gu,Seoul,Korea
Tel. +82 2-2026-2222
Fax. +82 2-2026-2113

DIMAC TOOLING PTY. LTD.
Oceania Contact

https://www.dimac.com.au

69-71 Williams Rd,Dandenong South,Victoria,3175 Australia
Tel. +61 3-9561-6155
Fax. +61 3-9561-6705

The products herein are controlled under Japanese Foreign Exchange and Foreign Trade Control Act.
In the event of importing and/or exporting the products, you are obliged to consult KITAGAWA as well as your government for t he related regulation prior to any transaction.