High Precise ER Type Spanner(Wrench) 1.Material:65Mn 1.ER8, ER11, ER16, ER20, ... ER 50 2.A,M,UM and K type ER spring collet spanner1.Type:ER 8, ER 11, ER 16, ER 20 ... 40 up to ER 50 2.Model:A type, M type, UM type and K type.3.Material:65Mn steel Package:Company profile:We ... tool series,collet series,boring heads series,etc.Sales covering the USA,Germany,Britain and regions in South Asia with increasing ...