To achieve the optimal surface finish on the OD of the ER collet, we have to precision grind the collet with the appropriate speed and feed for the right amount of time in the Shigiya grinder. We are not cutting corner in this grinding process time to increase the production. The OD makes contact with the bore on the tool holder and along with the internal bore tolerance itâs critical to be able to maintain the overall runout after a long period of usage.
Made from SUJ2 alloy steel from Japan which is equivalent to AISI 52100 and hardened to HRC 46-48
The 2 taper surfaces are precision ground in a CNC grinder Shigiya from Japan to roughness tolerance of Ra 0.4
An ER collet is selected during the CNC grinding process to check the 2 taper contact surface's accuracy"p" We optimize our manufacturing workflow for both efficiency and accuracy by utilizing robotic arms to load and unload ER collet stock into the Shigiya CNC grinders which are made in Japan. Combining the robotic arms with a reliable CNC grinder is our formular to control tight tolerance in a mass production environment. "p" Each collet is inspected 3 times at 0, 120, and 240 degree at 4 times diameter to the 5 micron (0.000197") runout tolerance. "p" This inspection process is also repeated 3 times with fully disassemble collet from the collet nut and the tool holder to consistent runout tolerance