The great Majority of routers employ a proprietary collet system that typically includes a 1/2″ collet and a 1/4″ collet.
When you need to use other sizes of end mills, use our collet adapter. It uses industry standard ER11 collets which range from .0394″ up to .276″.
shank diameter: 1/2″, shank length 1 1/2″
The included collet nut uses a 17mm wrench.
We recommend checking the run out at the ER11 collet bore when installing this adapter. Frequently the combination of the router manufactures tolerance in its collet bore and the 1/2″ collet results in excess run out of .008 inches or more. This can result in broken end mills, poor finish, or inaccurate hole sizes. We regrind the router collet bores or clock the router 1/2″ collet to neutralize the errors to .002 inches or less when we set up a new or repaired router.