The connecting rod converts the linear up and down movement of the piston into the circular motion of the crankshaft and is therefore subject to
tension, compression, bending and buckling.
The connecting rod is mounted on the crank pin of the crankshaft with a
plain bearing. The connecting rod bearing cap is bolted to the big end. In
most cases the connecting rod has oil duct in body to supply the gudgeon
pin with lubricant.
To obtain minimal weight and high strength, connecting rods are made
from different materials: Microalloyed steels; Sintered metals, High-grade
aluminium, CFRP and titanium (for high-performance engines)
Forged connecting rods exhibit a better strength-to-weight ratio and lower
costs than sintered connecting rods. Mass-produced connecting rods are
forged, cast or sintered.