Hardinge 16C Round Smooth Collet, 1/4" Hole Size Collet for holding workpieces in a lathe or other machine tool Size 16C round smooth collet with a through-capacity of 1-5/8 inches Back bearing diameter of 1-7/8 inches and overall length of 4-19/64 inches Heat-treated right-hand 1.870 inches x 1.75 millimeters external threads for long life Hardened and ground spring steel for accuracy and resistance to wear and breakage