A circle which is

A circle which is a simple closed shape on a plane

defined as “two dimensional Euclidean space” is the

aggregation  of all points on its plane that are at a

constant distance from a definite point“”0” called

center, There is one center in a circle、 and the only one

Exists there, 

a point length

Providing fresh fabarication method Ieveraging reliable technology and in-depth competencies
Jig geared to measurement of length:

"a point length"
Workload reduced and efficiency achieved by easy and  accurate diameter measurement (Patent pending : Length measurement jig) "a point length" as length measurement Jig provides a solution to an issue on soft jaw .fabrication for three-jaw chuck built in a lathe M/C.

This is because there is no diagonal measurement

point on a jaw . Intuition hence tells skilled operator  that applying the method of gauging is the best way instead.
This jig enables unskilled operator to implement accurate measurement   as well as reduce work and achieve efficient operation,

Standard type

  LEN-PM90  LEN-P300  LEN-P460  LEN-P700


Customized type
  LEN-PLM90  LEN-LP300  LEN-LP460  LEN-LP700

The jig dubbed as "a point length" provides easy and accurate measurement for both inner and outer diameters that enables an operator to reduce workload and achieve efficient works.

 Even though a three-soft jaw is widely employed at a lathe machine , the issue found in its
 attachment is that accurate diameter measurement is hard to be feasible since no diagonal
 measurement point is existed.

 Intuition was hence steering a skilled technician to apply the method of gauging , Which was the  best way. This has us contrary develop the unique jig that realizes accurate diameter measurement utilizing the theorem of a circle. Coupled with reducing workload and achieving efficient works, it is even possible that unskilled technician subsequently implement accurate measurement.

 Following eight products with sales price (consumption tax excluded ) as of Oct. 2015 are now available . Note that transportation fee intended for a domestic customer is burdened by us.

Material used:  Prehardened steel with HRC 42 as Rockwell hardness

Scroll chuck is amazingly converted into wide-profile soft jaw even as a 

small-sized chuck applied.


Small-sized chuck suitable for wide-profile soft jaw

Quest for wide-profile soft jaw even with small its size


The smaller a size of scroll chuck becomes, the narrower a width of soft jaw becomes. 

This symptom makes thinner workpiece made of aluminum and resin as well as shaped of 

ring vulnerable to scratches during chucking and warpage  


When scroll chuck is set on the outer jaw, it is became 

wide profile soft jaw, which enables stable fabrication of soft jaw to be feasible due to the 

fact that soft and outer jaws make configure cuneiform.


No additional soft jaw is needed at milling and machining while workpiece being chucked;

 following lathing is implemented since chuck holder is built in a scroll chuck. 

(Patents applied)



・Chuck maker: Kitagawa Iron works kobayashi Iron works and okukawa Iron works

For SC-3.SC-85: Wide-profile soft jaw

One set of S50C 16500yen (tax excluded)

One set of brazen BSM:19800yen(tax excluded)


・Chuck maker: TEIKOKU CHUCK

For MS-3: Wide-profile soft jaw

One set of S50C 17600yen(tax excluded)

Chuck holder for♯3:21000yen(tax excluded)


Small-sized chuck suitable for a fan-shaped soft jaw


Scroll chuck is amazingly converted into a

fan-shaped soft jaw chuck when you quest for a

wide-profile soft jaw even with a small-sized chuck.


Rings used in various spacers

When a workpiece is set on external jaws that imaginary perform a function as a wide-profile fan-shaped  

 soft jaw, which enables stable processing to be feasible due to the fact that soft and external jaws configure a cuneiform structure. This is the most suitable for either thinner or narrower width of ring-shaped     

 parts which is presumably susceptible to deformation or distortion during chucking operations.



● Chuck maker: Kitagawa Iron Works, Kobayashi Iron Works and Okukawa Iron Works

For SC-3, SC-85: Wide-profile soft jaw


 One set of S50C: 28,600 yen (tax excluded)

 One set of brazen BSBM: 30,000 yen (tax excluded)

● Chuck maker: TEIKOKU CHUCK

For MS-3: Wide-profile soft jaw

 One set of S50C: 30,000 yen (tax excluded)

 One set of brazen BSBM: 33,000 yen (tax excluded)


● Ishiai Precision made products

 Chuck holder for #3 (3 inches): 18,600 yen (tax excluded)

 Soft jaws and chuck holders for both #4 (4 inches) and #5 (5 inches): Built-to-order manufacturing

Scroll chuck is impressively 

converted into a soft-jaw chuck.


Soft jaw brings solutions for potential issues on scratches, deformation, distortion and/or surface wobbling detected at fabrication of rings or thinner parts when scroll chucks applied.


When a workpiece is set on external jaws of scroll chuck that imaginary perform a

function as awide-profile  soft jaw, which enables stable processing to be ensured due to the fact that soft and external jaws configure a cuneiform structure. Thus, simple and quick soft jaw processing is feasible without equipping with power chucks.


Emphasis on that our eye-catching device called a point length helps you quickly and productively fabricating soft jaws to meet required dimensions.




Note: Built-to-order manufacturing applied.

Ishiai Precision Co., Ltd,

799 Koaso, Ueda-shi, Nagano-ken 386-1213

Phone/Facsimile: +81-267-7635 /+81-268-7695


The eight Products shown above are now available. For more details, Please contact us by e-mail or fax.


Contact us.

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