Qualified connecting rod adopts hot forging integral molding craft with continuous metal fiber along rod body shape. Inferior connecting rod made from secondary stamping has broken fiber texture, easily bending or breaking under explosive combustion impact force inside cylinder. Visual inspection of forging texture can quickly distinguish raw material quality before batch procurement. Stable forging structure bears instantaneous high pressure generated during engine power stroke without permanent deformation.

The big end inner hole of connecting rod is matched with connecting rod bearing to wrap crankshaft journal for rotary movement. Unprocessed rough bore surface creates uneven contact between bearing and rod body, accelerating bearing local wear and clearance expansion. Digital boring processing polishes rod big end hole to fixed roundness standard, making bearing installation tight without loose shaking during engine high speed rotation. Uniform matching precision extends service life of matched crankshaft assembly.

Minor bending deformation of connecting rod cannot be identified by naked eye, but leads to piston inclined operation inside cylinder, scratching cylinder wall and tilting piston ring. All finished connecting rods pass straightness detection equipment screening before leaving warehouse to eliminate pre deformed products. Using untested bent connecting rod will cause irreversible scratch damage to cylinder liner and piston after short running mileage, generating expensive cylinder overhaul cost for vehicle owners.

Connecting rod cap is fixed with cylinder head bolts to form complete connecting rod assembly. Rough uncalibrated thread will slide during high temperature expansion, causing rod cap loosening and separation during engine operation. Standard thread tapping craft controls thread pitch and depth error within tiny range, matching supporting high strength bolts to maintain long term locking tightness. Reliable thread structure avoids sudden connecting rod separation that destroys whole engine assembly.