CNC spindle was made of special material :40Cr or 65Mn. HRC43-48 .welcome for more inquiry we supply cnc motor spindles for engraving milling ,it was made of special material 40Cr or 65Mn and Hardness :43-48 .the goods are most exported to taiwan area,germany, spain ,and other regions of the world , we offer the best price and quality , welcome for more inquiry