... aluminium-alloy for pneumatic cylinder ,ISO 6431,DNC,MB,DNG,SC,,SU,TN,STM,CK diameter form 32mm~320mm2:Surface treatment ... :We have many linear cutting machine ,high speed CNC machine,EDM spark machines,Drill machine ,die casting machine from 160T~800T also available!8 ... different kind mold according to customers request!! die casting parts SC piston for air cylinder(air cylinder piston)