【Fetures】- R8 Collets do not collapse. The Tail Thread Is M12; Tooth Type: Coarse Teeth; Precision: 0.013mm; Hardness(HRC): HRC55; Clamping Range (Inner Diameter): 10mm / 0.39-inch. 【Material】- Using high quality 65Mn alloy steel, hardened, long life and more durable. Precision ground to close tolerance. Positioning slot make the collets more quickly and convently to install. 【Advantage】- Large clamping force, wide glamping range, not aasy to wear, strong and durable. Surface grinding to ensure tolerance and accuracy, strong versatility and reliable. 【High Quality 】- Hardened and ground throughout Superior quality R8 Collets Set. Precision Thread Hole allows the collet to be quicky connected with pull rod. The silver color looks perfectly cool, also providing more conveniently function. 【Application】- Spindle is R8 taper that any R8 shank will fit. It used for clamping tools,change the taper hole of spindle,It is easy to use,to enlarge the use range of machine tool.