Collet Chuck, ER-20, R8, Professional Grade 

R8 to ER-20 professional grade collet chuck. Premium 20CrMnTi alloy steel hardened and all ground body for extended tool life.

The maximum RPM is 8,000 and the maximum runout is 0.0002" (0.0058 mm). The R8 drawbar thread is 7/16"-20.

ER-20 collets have a range of 1/16" to 1/2" (1.0 mm to 13.0 mm).

*Collet must be assembled into a collet chuck nut before inserting into the collet chuck.