Dongfeng Renault engine parts Connecting rod screw D5010224123

Crafted from 42CrMoA alloy steel—a premium material for high-stress engine components—this connecting rod screw delivers exceptional tensile strength (1,200 MPa) and yield strength (1,000 MPa). The steel undergoes a quenching and tempering process that enhances its hardness (HRC 32–35) and impact resistance, allowing it to withstand the extreme dynamic loads of engine operation (up to 50 kN per screw during combustion cycles). Unlike standard carbon steel screws that stretch or break under high stress, this alloy steel design maintains structural integrity even in high-performance or high-mileage Dongfeng Renault engines. Rigorous load testing confirms the screw endures 100,000+ combustion cycles without deformation, ensuring reliable power transmission between the connecting rod and crankshaft

The screw features a precision-rolled thread with a 60° V-thread profile, engineered to maximize thread engagement with the connecting rod’s threaded holes. The threads are manufactured with a class 5g tolerance (for external threads), ensuring uniform contact pressure across the thread surface and minimizing stress concentration. Additionally, the screw’s thread root is radius-ground (0.15mm radius) to prevent crack initiation— a common failure point in low-quality screws. When torqued to Dongfeng Renault’s specified value (45–50 N·m), the precision threads create a tight, vibration-resistant fit that retains torque even during engine startup or high-speed operation (up to 5,000 RPM). This design eliminates screw loosening (a major cause of connecting rod failure) and ensures consistent clamping force on the connecting rod

To address the constant vibration of engine operation, the screw integrates anti-loosening and anti-fatigue enhancements. The screw head features a serrated underhead (30° serration angle) that digs into the connecting rod’s surface when torqued, creating a mechanical lock that resists rotational loosening. The shank is also heat-treated to improve fatigue resistance, with a surface finish (Ra ≤ 0.8μm) that reduces stress corrosion. Unlike screws with plain underheads that loosen over time, this serrated design maintains torque retention for the engine’s entire service life. Additionally, the screw is coated with a zinc-phosphate layer that enhances lubricity during installation, ensuring uniform torque application and preventing thread galling (metal-to-metal adhesion) that can damage the connecting rod’s threads

Each connecting rod screw undergoes strict quality control measures to meet Dongfeng Renault’s engine standards. Key tests include: dimensional verification via laser scanning (to confirm thread and length accuracy), tensile testing (to validate strength), torque-retention testing (to ensure anti-loosening performance), and fatigue testing (to simulate long-term engine operation). The screw is manufactured in an IATF 16949 certified facility and complies with international standards for engine fasteners (ISO 898-1). It also includes a traceability code that links each unit to its production batch, raw material source, and test results—allowing for full quality tracking. Backed by a 24-month warranty against manufacturing defects (e.g., thread damage, material cracking, or torque loss), it provides Dongfeng Renault engine owners with reliable connecting rod performance and long-term peace of mind