Bolton Tools CAT40 Precision ER Tool Holders | CAT40-ER20 4"
Finish: Black Oxide
Runout: .005mm/.0002in TIR
Works on all CAT 40 machines
All critical tool holder surfaces precision ground
Made from alloy structural steel hardened to 48 - 52rc
8000 rpms
Rear thread for pull stud is 5/8‘11