0.00024 at collet face. Rear thread for pull stud is 1 - 8. Balanced to G6.3 at 10000 rpm. Works on all CAT 50 machines. All critical tool holder surfaces precision ground. Made from alloy structural steel hardened to HRC48 - 52 for long, durable service life. Taper ground to high precision AT3 accuracy. Collet Chuck accepts all ER25 collets. 10.4 × 4.3 × 4.3 in.