Piston : Automotive type low expansion aluminium alloy . Cylinder : Special cost iron, deep finned for quick heat dissipation .Valve Plates : Special Stainless steel material for high resistance and efficiency and for self floating .Inter After Cooler : Deep finned aluminium alloy specially designed to keep temperatures low and minimize formation of carbon . Crank Shaft : Made of Carbon steel dynamically balanced with roller bearings . Diaphragm Pressure Switch : For efficient automatic On and Off automatic venting and noload restarting of compressor units, pressure switch pressure switch with electromagnetic unloader is provided.