1.Certification:ISO/TS16949 2.Material:carbon steel,alloy steel 3.Surface treatment: anodized, descale, Shot-blasting CONNECTING ROD --AUTO CRANK MECHANISM--AUTO ENGINE ... rotating motion. The main specification : The main car modlesCertificationISO/TS16949AudiWorkmanshipdie forging,roll forging, machining, heat treatmentMercedes-BendzMaterialsmiddle carbon steel, alloy steelBMWStructuresmall end ...