... material steel:40Cr ER collet is one kind of the Spring Collet and it is usually to be used with ... how to make ER collets.We choose the high grade spring steel-65 Mn as the material,so we can ... machine with high speed, high precision, strong stability and good balance. QuFu ChongDe Precision Machinery Co., Ltd can provide various ... the world! er collet, SK collet, collet, collets, ER spring collet