PRO-SERIES PRO-SERIES HIGH ACCURACY ER-20 1/2″ SPRING COLLET (3901-5191)

Pro-Series High Accuracy ER-20 1/2″ Spring Collet (3901-5191) ~ AA Grade. ~5 Micron. ~ Superior finish. ~ Runout is less than or equal to .0002″. ~ Made of high grade SUJ2 steel. ~ Hardened and precision ground to 44-48HRC. ~ Exceeds Federal Specifications. ~ Major diameter is .830″. ~ Overall length is 1.230″. ~ Inside diameter is ground to reach mirror finish increasing grip force. ~ Surface treated to reduce rust and improve hardness. ~ Cryogenic treatment to significantly increase wear resistance. ~ Collet must be assembled into collet chuck nut before inserting into the collet chuck. AA Grade. 5 Micron. Superior finish. Runout is less than or equal to .0002″. Made of high grade SUJ2 steel.