ER Collets 1.Material: 60Mn 2.Accuracy:0.005mm 3.Power clamping ability 4.Hardness:HRC44-48 Products Features:ER ... , drilling, tapping, grinding and engraving operation etc.5.Models: ER8, ER11,ER16,ER20,ER25,ER32,ER40,ER50.6 ... China. We can suplly various machinery accessories such as Er collet, Sealed collet, Tap collet, R8 collet, 5C ... please kindly feel free to contact us. ER Collets Manufacture