Accusize Morse Taper #3 MT3 Round Collet Set, 7 Pc, 1/8-3/4 In, 0223-0312 | 0.0006 In TIR, Hardened Spring Steel, 3/8-16 Drawbar Thread, Fitted Case. Manufacturer: Accusize Co., Ltd. Morse Taper 3 Round Collet Set, 7 Pcs/Set, 0223-0312 Morse Taper 3 Round Collet Set, 7 Pcs/Set, Size Including 1/8″, 3/16″, 1/4″, 3/8″, 1/2″, 5/8″, & 3/4″, 0223-0312 Threads for drawbar: 3/8″-16 Hardened and ground Accuracy: 0.0006″ TIR Used to hold tools with better accuracy (less run-out) than a chuck.