ER Collets Made of special elastic steel material:65Mn ER8,ER11, ER16, ... , ER32, ER40, ET50 USed for boring,milling,d ER ColletsER Collets, full sizes from ER8 till ER50, high precision, made from ... 65Mn.ER Collets, detailed sizes are as below: ER89PCS1-5mm (1, 1.5 ...