Bolt used for fastening camshaft and variable camshaft timing sprockets.
Must be able to guarantee a precise axial load since their purpose is to keep the gears or variable camshaft timing in perfect synchronization in relation to the crankshaft thus ensuring correct engine operation.
They have a 10.9 strength rating and increasingly more a 12.9 rating, often designed with custom strength ratings, even with very narrow Rm ranges. They work in the plastic range and are usually tightened based on torque + rotation. They have an external driver head, may require a washer. They must not have any tendency to come loose, thus in certain cases they may be manufactured with plastic blocking components.