Engine Flywheel Screw

Function
1. Secure the flywheel firmly onto the rear end flange of the crankshaft to transmit the output torque of the engine.
2. Utilize the pre-tightening force of the bolts to generate friction, preventing the flywheel from slipping or loosening under alternating torque and impact loads.
3. Stabilize the rotational inertia of the flywheel to ensure smooth transmission at the clutch / output end.
4. Resist the alternating tensile and shear forces caused by engine vibration, start-stop impacts, and thermal expansion and contraction.

Characteristics
1. High-strength special fasteners, mainstream grades: 10.9 grade / 12.9 grade, cannot be replaced by ordinary bolts;
2. High thread accuracy, heads mostly in hexagonal or 12-point梅花 shape, facilitating uniform tightening according to the specified torque;
3. Quenched and tempered heat treatment, controlling the elongation rate, allowing for reasonable elastic pre-tightening;
4. Surface blackening / phosphating / Dacromet anti-rust treatment, resistant to high temperatures and fatigue;
5. One-time-use parts: must be replaced after disassembly; stretching fatigue damage is invisible to the naked eye, and reinstallation is prone to fracture;
6. There are strict tightening sequences + torque requirements, step-by-step locking diagonally to avoid flywheel skew.