R8 Collet 10mm Metric Mill Chuck Holder 65Mn Spring Steel 7/16-20UNF Thread

Clamping Diameter: 10mm / 0.39-inch Drawbar Thread: 7/16-20UNF Material: 65Mn Spring Steel Hardness: HRC 55 Accuracy: 0.0005-inch (0.013mm) Total Length: 104mm / 4.09-inch Top Diameter: 32mm / 1.26-inch Bottom Diameter: 24.1mm / 0.95-inch This unit is applicable to all sorts of milling machines which spindle taper hole is R8.