Reciprocating piston compressor power machinery and used to connect the piston rod and crank. Many pieces of steel rod, the main part of the section for many round or shaped, both ends have holes, holes with a bronze bushing or needle bearing for the pin into the shaft consisting articulated. linkage of the major forms of damage are fatigue fracture and excessive deformation. Usually the site of fatigue fracture in the connecting rod on the three high-stress region. Connecting rod requirements of working conditions with high strength and anti-fatigue properties; Also requires enough steel and toughness.