Iscar Milling Tip Insert Holder, Series: MULTI-MASTER, MM S-A Tool Holder, Stepped Cylindrical Shank, 0.31 in Shank Diameter, 0.6 in Effective Length, 2-1/2 in Overall Length, Steel Tool Holder, T05 Neck Thread, 0.3 in Diameter Neck, 0.51 in Head Length