The cylinder head main bolt is the cornerstone of your engine’s sealing integrity, clamping the cylinder head to the block with immense, precisely controlled force. The 612600040452 Cylinder Head Main Bolt from HOWO is engineered to deliver exceptional tensile strength, consistent clamp load, and a perfect factory fit, ensuring that your head gasket remains sealed under extreme combustion pressures and thermal cycling. As a vital Howo/Sitrak truck parts component, this main bolt is manufactured from high-grade micro-alloyed steel with precision-rolled threads and a durable corrosion-resistant coating, providing the reliable torque retention and fatigue resistance demanded by modern heavy-duty diesel engines. Whether you are replacing a head gasket or performing a complete engine rebuild, the 612600040452 guarantees a flawless OEM fit, consistent clamping force, and extended engine life – making it the trusted choice for professional workshops and fleet operators worldwide.
The cylinder head main bolt is not just a fastener – it is a precision-engineered component that must maintain a precise clamp load over the entire life of the engine. The 612600040452 is specifically designed for HOWO MC11 and MC13 engine families, providing the exact clamping force required to keep the cylinder head securely mated to the block, preventing combustion gas leakage, coolant mixing, and oil contamination. A single failed or stretched bolt can lead to head gasket failure, which often results in costly downtime and extensive repairs. HOWO has crafted this bolt using a micro-alloyed steel that is heat-treated to achieve a tensile strength of 1200 MPa, with rolled threads that eliminate stress risers and ensure consistent torque-to-yield performance. Its zinc-nickel plating offers superior corrosion resistance, ensuring that the bolt remains serviceable even after years of exposure to hot oil and coolant. With the 612600040452, you restore the original clamping integrity, protect your head gasket, and ensure that your engine delivers the power, efficiency, and reliability that professional drivers and fleet managers demand.
Superior Strength
1200 MPa
Corrosion Guard
Zinc‑Nickel
OEM Fit
Exact Match
Heat Resistant
Fatigue Proof
The 612600040452 cylinder head main bolt is manufactured to the highest OEM standards, incorporating advanced materials and precision engineering. Below are the complete technical specifications for this essential engine fastener.
| Parameter | Specification | Detail |
|---|---|---|
| OEM Number | 612600040452 | Exact Match |
| Part Name | Cylinder Head Main Bolt | HOWO Genuine |
| Brand | HOWO | Original Equipment |
| Application | HOWO T7H / A7 / MC11/MC13 | Cylinder head clamping |
| Material | Micro-alloyed steel (42CrMo4) | Heat-treated |
| Thread Size | M14 x 1.5 | Precision rolled |
| Overall Length | 145 mm | Under head |
| Strength Grade | 12.9 | High tensile |
| Head Type | Hexagon socket / 12‑point | High torque |
| Surface Finish | Zinc‑nickel plating | Corrosion resistant |
| Torque Specification | 120 Nm + 90° angle | Yield point method |
| Weight | 0.15 kg | Complete |
| Warranty | 12 Months | Manufacturer Guarantee |
The 612600040452 cylinder head main bolt is the product of advanced cold‑heading and thread‑rolling technologies that preserve the material’s grain flow, significantly enhancing its fatigue resistance. The micro‑alloyed steel composition, combined with a controlled quenching and tempering process, yields a tensile strength of 1200 MPa while maintaining the ductility required to absorb the elastic deformation that occurs during cylinder head clamping. The threads are rolled, not cut, which eliminates stress risers and ensures that the bolt achieves the correct clamp load with every installation. The under‑head radius is precisely engineered to distribute clamping force evenly, reducing stress concentration on the cylinder head and washer. The zinc‑nickel plating provides outstanding corrosion protection, ensuring that the bolt can be removed easily during future service intervals. Each bolt is inspected for dimensional accuracy, hardness, and surface integrity, guaranteeing that the 612600040452 meets HOWO’s stringent quality standards. This meticulous engineering ensures that your cylinder head remains securely clamped, the head gasket maintains its seal, and your engine operates reliably under the most demanding conditions.
The 612600040452 cylinder head main bolt is specifically designed for HOWO heavy‑duty trucks equipped with MC11 and MC13 engine families, including T7H, A7, and derivative models. It directly replaces the original bolt with identical thread size, length, and clamping characteristics, ensuring a straightforward installation without modifications. The bolt is compatible with all factory‑specified cylinder heads, washers, and tightening procedures, and it works seamlessly with the original equipment head gasket. This cylinder head main bolt is also compatible with many Sinotruk and other commercial vehicles that share the same engine architecture. To confirm fitment, always cross‑reference the OEM number on your existing bolt with 612600040452. If they match, this component will integrate seamlessly. Keeping these bolts in your spare parts inventory ensures that you can perform head gasket replacements or engine rebuilds without delay, minimising downtime and preserving the performance and reliability of your engine.
HOWO T7H
Primary Fitment
HOWO A7
Also Compatible
MC11/MC13
Engine Series
Direct Replacement
No Modifications
Replacing worn, stretched, or damaged cylinder head bolts with the 612600040452 immediately restores the original clamping force and head gasket sealing integrity of your engine. The precise torque retention and high tensile strength ensure that the cylinder head remains securely attached to the block, even under the extreme pressures and thermal cycling of heavy‑duty operation. This prevents head gasket failures, coolant leaks, and compression loss, which can lead to reduced power, increased fuel consumption, and engine damage. The consistent clamp load also minimises the risk of cylinder head warping, extending the service life of both the head and the gasket. The corrosion‑resistant coating ensures that the bolts remain easy to remove during future service, reducing the risk of seized or broken bolts. For fleet operators, reliable cylinder head bolts reduce the risk of engine failures, lower maintenance costs, and help maintain the performance and efficiency of your vehicles. By investing in the 612600040452, you ensure that your HOWO engine delivers the power, reliability, and durability that professional drivers and fleet managers depend on.
Installing the 612600040452 cylinder head main bolt is a critical procedure that requires precision and the correct tools. Begin by thoroughly cleaning the bolt holes in the engine block and the cylinder head bolt seats, ensuring they are free of oil, debris, and old thread sealant. Apply a thin layer of thread lubricant (e.g., molybdenum disulphide) to the bolt threads and under‑head washer to ensure accurate torque readings. Carefully install the new bolts, tightening them in the correct sequence and in multiple stages to the manufacturer’s specified torque and angle. Use a calibrated torque wrench and angle gauge to achieve the final yield‑point torque. After installation, run the engine to operating temperature, allow it to cool, and then re‑torque the bolts as specified in the service manual. Periodically inspect the bolts for signs of corrosion or damage during routine maintenance. With proper installation, the 612600040452 will provide years of reliable clamping performance.
Pro Tip: When replacing cylinder head bolts, always replace all bolts as a set, even if only one is damaged. Using old bolts with new ones can lead to uneven clamp load and head gasket failure. The 612600040452 is available individually; order the required quantity for a complete set to ensure consistent clamping force and engine integrity.
Genuine HOWO components are engineered to the highest standards, and the 612600040452 cylinder head main bolt is no exception. Aftermarket bolts often use inferior steel, inconsistent heat treatment, or imprecise thread geometry, leading to incorrect clamp loads, premature stretching, or bolt failure. HOWO’s bolt is manufactured using the same materials and processes as the original equipment, guaranteeing a perfect fit and reliable performance. By choosing the 612600040452, you benefit from HOWO’s rigorous testing, including tensile strength, fatigue, and corrosion resistance tests. This ensures that the bolt meets the demanding requirements of heavy‑duty trucking. Moreover, genuine parts are backed by a comprehensive warranty and supported by HOWO’s global network, giving you confidence in your purchase.
OEM Authentic
Factory Quality
Long Service
Extended Life
Global Standard
Trusted Worldwide
Q: Which vehicles use the 612600040452 cylinder head main bolt?
A: The 612600040452 is designed for HOWO T7H, A7, and other models with MC11/MC13 engines, as well as many Sinotruk trucks with the same engine architecture.
Q: What are the symptoms of a failed cylinder head bolt?
A: Loss of engine power, coolant or oil leaks around the cylinder head, overheating, white smoke from the exhaust, and visible head gasket failure are common indicators.
Q: Can I reuse the old cylinder head bolts?
A: No, cylinder head bolts are designed as single‑use fasteners. Once torqued to yield, they stretch and cannot reliably provide the correct clamp load. Always install new 612600040452 bolts when performing a head gasket replacement.
Q: How do I verify the correct part?
A: Check the OEM number on your existing bolt. If it matches 612600040452, this is the exact replacement. Consult your vehicle’s parts manual for additional confirmation.
Order your 612600040452 Cylinder Head Main Bolt today! Explore our complete selection of genuine HOWO and Sinotruk engine components at Howo/Sitrak truck parts and keep your engine sealed and performing at its peak.
The 612600040452 Cylinder Head Main Bolt from HOWO is a testament to precision engineering and uncompromising quality. By choosing this genuine component, you ensure that your engine’s cylinder head is securely clamped, the head gasket maintains its seal, and your engine delivers the power, reliability, and durability required for modern heavy‑duty trucking. Whether you are a professional engine builder or a fleet manager, this main bolt offers the performance, reliability, and exact fit that you can count on. Trust HOWO – the benchmark for excellence in heavy‑duty truck components – and experience the difference that genuine quality makes.
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