ER NUTS (DIN 6499-D & E) 1.material:spring steel 2.specification: ... M/UM/KM 3.standard: DIN6499 ER NUTS (DIN6499 D & E )1.material:spring steel2.specification: A/M/ ... and marketing of machine tool accessories.Production includes milling chuck series,CNC tool series,collet series,boring heads series ... ,tapping chuck series,pull studs,er nuts,centers,mores taper ...