Cylinder head bolts are the only fasteners holding the cylinder head against the block, compressing the head gasket to maintain both coolant and combustion sealing across the full working temperature range of the engine. Most modern designs use torque-to-yield bolts — a one-time-use fastener that is stretched during tightening beyond its elastic limit and must never be reused. Reusing a spent bolt risks under-clamping the gasket, which is one of the leading causes of premature head gasket failure and the white-smoke-from-the-exhaust symptom that signals coolant entering the combustion chamber. A cylinder head bolt set from Victor Reinz or Elring supplies the correct number of bolts in the correct grade, length, and thread form for your specific engine, with torque and angle-tightening values referenced directly to the vehicle manufacturer's sequence. The OE set reference matters because bolt length varies by position on many multi-valve heads, and mixing lengths can bottom a bolt in a blind hole before achieving correct clamping force. Bolt sets are almost always renewed as part of any head gasket replacement, timing belt replacement where the head must be disturbed, or engine overhaul — they are a low-cost insurance policy against the most expensive possible engine failure.
Cylinder head bolt specifications are unique to an engine code, not just a model name. Variables include bolt diameter, thread pitch, overall length (which can differ by position on the same head), material grade, and whether the design is torque-to-yield or conventional. Use the engine-code selector on this page alongside your VIN to filter to the exact set. The OE reference confirms that every bolt in the kit was validated for your head casting, tightening sequence, and torque-angle specification — mixing in bolts from a different set is a common source of repeat head gasket failures.
Torque-to-yield bolts, which are used on the vast majority of modern engines, must not be reused. Once tightened to their yield point they are permanently stretched, and a re-torqued stretched bolt will not reach the required clamping load — it will feel tight but will not compress the head gasket to specification. The consequence is a head gasket that fails within a short period of driving. Always fit a new OE-specification bolt set whenever the cylinder head is removed, regardless of how intact the old bolts appear visually.
OEM cylinder head bolt sets from suppliers like Victor Reinz and Elring are manufactured to precise metallurgical grades, with yield strengths and elongation characteristics validated against the engine manufacturer's tightening specification. Reputable aftermarket sets from AJUSA or BGA meet the same standards. Under-specification bolts — those with lower yield strength — can appear to tighten correctly but fail to maintain clamping force once the engine reaches operating temperature, leading to head gasket lifting. The OE part reference is the confirmation that grade and length match.
A bolt that breaks during tightening — often a sign that a torque-to-yield bolt was reused — requires extraction from the block, which can mean helicoil thread repair if the hole is damaged. A bolt that loses clamping force in service allows the head gasket to lift locally, creating a path for combustion gases to enter the coolant circuit. The symptoms are overheating, white or grey exhaust smoke, oil and coolant mixing, and bubbling visible in the coolant reservoir. Repairs at that stage involve at minimum a new head gasket and head skim, and potentially a cracked or warped head.
Showing 100 of 3,417 Cylinder Head Bolt Set OE numbers. Enter the OE on the main OE search to jump to any reference.
