Secure your rotating assemblies with the 612600020040 Square and Rectangular Key, a precision‑engineered mechanical fastener that provides positive, backlash‑free torque transmission between shafts and hubs. This key is manufactured from high‑strength alloy steel with a controlled surface finish, ensuring reliable performance in the most demanding heavy‑duty applications. As a critical part of genuine Howo/Sitrak truck parts, the 612600020040 is produced to exact OEM specifications, guaranteeing a perfect fit in HOWO, Sitrak, and Shacman power trains, timing gear drives, and auxiliary systems. Whether you are rebuilding a gearbox, replacing a worn key on the crankshaft, or securing a pulley, this key delivers the strength, accuracy, and durability required to prevent shearing, reduce downtime, and keep your equipment running at peak efficiency.
The 612600020040 is not an ordinary key stock; it is a precision‑ground key that ensures exact fitment and reliable torque transfer. Manufactured from case‑hardened alloy steel, this key offers a hard outer surface for wear resistance and a tough core to absorb shock loads. The key’s cross‑sectional dimensions are held to tight tolerances (typically ±0.025 mm on width and thickness), guaranteeing a precise fit in the shaft keyway and hub keyway. The ends are chamfered to facilitate assembly, and the surface is treated with a corrosion‑resistant coating to prevent rust. Whether it’s a square key with equal width and height or a rectangular key with unequal dimensions, the 612600020040 is designed to handle the shear and compressive stresses encountered in heavy‑duty power transmission.
The key’s material and heat treatment are optimized to withstand the torsional vibrations and peak torque events common in diesel engines. The case depth is controlled to provide a hard, wear‑resistant surface while maintaining a ductile core that resists fracturing under impact loading. This balance of properties ensures that the key can be reused during maintenance cycles, provided it is not damaged. The 612600020040 is compatible with both parallel and tapered keyways, making it versatile for various applications within the driveline.
High Shear Strength – The 612600020040 is engineered to handle the full torque output of modern diesel engines, preventing key shearing and subsequent component damage.
Precision Fit – Ground to exact dimensions, the key ensures zero‑backlash engagement, eliminating impact loads that can fatigue the keyway edges.
Case‑Hardened Surface – The hard outer layer (58–62 HRC) resists wear from fretting and micro‑movement, while the tough core absorbs shock loads.
Corrosion Resistance – The protective coating prevents rust and corrosion, ensuring easy removal during maintenance and preserving the keyway surfaces.
The 612600020040 is dimensionally identical to the original equipment key used in HOWO, Sitrak, and Shacman heavy‑duty applications. It is specifically designed for use on the crankshaft, camshaft, gearbox input shafts, and PTO drives of the WP10, WP12, WP13, and WD615 engine families. The key’s width, height, and length match the keyway slots machined into these components, ensuring a positive fit that prevents movement and wear. By choosing this genuine key, you eliminate the risks associated with aftermarket keys that may have incorrect dimensions, inferior material, or poor heat treatment, which can lead to keyway fretting, shearing, and catastrophic failure of the driveline.
The 612600020040 has been proven in field tests to withstand the high torque and vibration levels of heavy‑haul applications. Fleets that have standardized on this key report fewer keyway repairs and less downtime due to driveline failures. Its reliable performance ensures that power is transmitted efficiently without loss, contributing to better fuel economy and reduced emissions. The key is also easy to install and remove, making it a preferred choice for maintenance teams.
Installing the 612600020040 correctly is crucial for ensuring reliable torque transmission. Before installation, thoroughly clean the shaft keyway and the hub keyway using a solvent and a stiff brush to remove any debris, old sealant, or burrs. Inspect the key for any nicks or damage; if imperfections are present, replace the key. Apply a thin layer of anti‑seize compound or light oil to the key surfaces to facilitate installation and future removal. Gently tap the key into the shaft keyway using a soft‑faced mallet until it is fully seated. The key should slide into place with slight resistance; if it is too tight, check the keyway dimensions for wear or burrs.
Once the key is seated, slide the hub (gear, pulley, etc.) over the shaft, ensuring the key aligns with the hub keyway. The hub should slide on with moderate pressure; if excessive force is required, verify the key and keyway dimensions. After assembly, tighten the retaining bolt or nut to the manufacturer’s specified torque. The 612600020040 does not require any special post‑installation procedure, but it is recommended to re‑check the torque after the first few hours of operation. With proper installation, this key will provide a lifetime of trouble‑free service.
Each 612600020040 key is produced in an ISO 9001‑certified facility with stringent process control. The steel is sourced from approved mills and is spectrographically analyzed to verify its composition. After forging or shearing to length, the key blanks are heat‑treated using a controlled atmosphere furnace to achieve the specified case depth and core hardness. The keys are then precision‑ground on all four sides to achieve the required dimensional tolerances. A 100% dimensional inspection is performed using optical comparators and micrometers to ensure that width, height, and length are within the narrow tolerance band.
Random samples from each batch undergo hardness testing (surface and core), a micro‑structure examination, and a shear strength test. The key’s surface finish is also measured to ensure it meets the specified roughness. This comprehensive quality regimen guarantees that every 612600020040 delivers the same reliable performance as the original OEM key, giving you absolute confidence in your assembly.
Technicians and fleet maintenance teams across the globe rely on the 612600020040 because it eliminates guesswork and ensures a positive, secure fit every time. The key’s precision grinding and consistent dimensions mean that it can be installed without filing or modification, saving valuable workshop time. Many experienced mechanics report that using this genuine key has virtually eliminated key‑shearing failures and associated damage to shafts and hubs, resulting in fewer roadside breakdowns and lower operating costs.
The 612600020040 is also available in convenient multipacks for fleet inventory management. Its durable coating protects against corrosion during storage, ensuring that the key is ready for use when needed. When you choose this key, you are selecting a component that has been proven in the harshest environments, offering the perfect combination of strength, precision, and reliability.
In summary, the 612600020040 Square and Rectangular Key is a precision‑engineered fastener that ensures reliable torque transmission and protects your driveline from costly failures. Its high‑strength alloy construction, precision grinding, and rigorous quality control guarantee a perfect fit and long service life. By investing in this genuine OEM‑grade part, you are safeguarding your shafts, gears, and hubs from keyway wear and shear failure, ultimately extending the life of your equipment and reducing maintenance costs.
Don’t settle for generic keys that can compromise your driveline integrity. Choose the 612600020040 for your next repair or rebuild. With its proven track record and widespread acceptance among professionals, this key is the smart choice for anyone who values reliability, safety, and performance. Keep your power flowing smoothly and securely with the 612600020040 – the definitive choice for HOWO and Sitrak drivetrains.
We are a heavy-duty truck parts store. Please leave your contact information and inquiries. We will respond within 12 hours.
