Professional Grade Bolton Tools ER20 1/2" Ultra Precision ER Collet Runout is 0.0003"

1. Hole Diameter: 1/2″, overall length is  1.240”

2. Material: High Grade JIS-SUJ2

3. Clamping Range:  0.500″-0.460″

4. Hardness: 46-50 HRC

5. Good elasticity, high precision, Run-Out Tolerance ≤ 0.0003″                 

Product Description

chongde ER20-1/2″ Precision Spring Collet Clamping Range 0.500″-0.460″

A new process quenching treatment for collets, which has a decisive influence on product accuracy, service life and stability.

Quenching is a high-frequency aging treatment added to the heat treatment, -384.8℉ degrees cryogenic treatment, these are not reflected in the appearance, but have a decisive impact on the service life and stability of the product. 

Processing technology, full-line CNC internal hole grinding machine, compared with the products processed by ordinary internal hole grinding machine, the inner hole straightness is better, the finish is better.

Cryogenic treatment

1) -384.8℉, and ultra long cryogenic treatment make the nearly all retained austenite change to martensite.
2) The precipitated nano carbide particles increase the hardness and toughness of the material.
3) Remove the internal stress of the residual material.
4) After cryogenic treatment, the wear resistance of products is significantly improved, and the accuracy and service life

   of repeat clamping can be increased by about 50%.

This collet size is true fractional size, not a metric converting size and the surface on this collet has been specially treated to increase its tool life.  Runout is 0.0003″.