Hardinge 1C Round Smooth Collet, 0.50mm Hole Size Collet for holding workpieces in a lathe or other machine tool Size 1C Round Smooth collet with a through-capacity of 1/4 inch Back bearing diameter of 0.335 inch and overall length of 1.438 inches Heat-treated right-hand 0.322 inch x 40 external threads for long life Hardened and ground spring steel for accuracy and resistance to wear and breakage