Protorque Head Bolt Set BK5323

Cylinder head bolts are the connecting elements between the cylinder head and the cylinder block of the engine. They hold the cylinder head with high loads to the engine block and the head gasket and help the gasket to seal properly. When being torqued up, the bolt's force is being distributed across the sealing surface and generates surface pressure to create mutual sealing of combustion chamber, lubricant and coolant channels and the ambient air.

Head bolts are generally categorised into conventional and torque-to-yield head bolts. Conventional head bolts, commonly known as either unstretched bolts or roll-shaft bolts, feature straight-on-line threads. Torque-to-yield head bolts, namely stretched bolts or reduced-shaft bolts, are with threads that are not straight-on-line. Both types of bolts are tensioned until they deform, but torque-to-yield bolts can be tightened beyond their elastic limit into the plastic phase, delivering high and uniform clamping forces.

Warranty

3 years or 60,000km, whichever comes first.