ENGPAR Sales Pvt. Ltd. Offers Alloy Steel Piston Pin. ENGPAR Sales Pvt. Ltd. Supplies piston rings. Alloy Steel Piston Pin is provided with the hardness of between 55HRC to 60HRC, which can be altered according to customer need or OEM specifications. Alloy Steel Piston Pin is made for a wide range from diameter 28mm to 58mm. These piston pins covers all applications of automobiles, tractors, diesel and industrial engines, air & gas compressors.