This bolt secures the cylinder head to the engine block, maintaining the clamping force required to contain combustion pressure and seal the head gasket. It is installed in the threaded bores around the cylinder head perimeter and works with the gasket to prevent coolant and compression leaks. A bolt that has been stretched or corroded will not hold the specified torque, leading to gasket failure and loss of compression. This component is manufactured to the original hardness specification, which ensures it reaches the correct preload without exceeding the material's yield point during tightening. On reinstallation, clean the threads and the bolt shoulder, apply light oil to the threads, and tighten in the sequence and torque range specified for the engine.