Gearbox Bolts

The gearbox bolts is part of an integrated fastening solution specifically engineered for automotive and motorcycle transmission systems. It includes housing bolts, gear shaft bolts, synchronizer fasteners, and oil pan bolts, all designed to ensure precise positioning and secure connections of internal gears, shafts, and synchronizers. This gearbox bolt withstands high-frequency impact, torque, and vibration during operation, guaranteeing smooth and efficient power transfer across manual (MT), automatic (AT), CVT, and dual-clutch (DCT) transmissions, making it essential for transmission durability and safety.

The entire gearbox bolts series complies with ISO 898-1 Grade 8.8+, SAE J429 Grade 8 / 10.9, and GB/T 3098.1 standards. Materials such as 42CrMo and 35CrMo alloy steel, as well as SUS316 stainless steel, are selected based on load requirements. Key fasteners undergo quenching, tempering, and induction hardening to achieve property classes 10.9–12.9, with tensile strength ≥ 1040 MPa and yield strength ≥ 940 MPa. Advanced coatings such as Dacromet or Zn–Ni alloy provide salt spray resistance exceeding 500 hours, ensuring stable performance in oil-immersed, high-temperature (≤ 180 °C) environments.

Covering thread sizes from M6 to M20 and lengths from 5 mm to 100 mm, the gearbox bolt is available with external hex, internal hex, or flange heads, featuring 6g thread accuracy and tightening torque variation of ≤ 2%. We offer tailored fastening kits for different transmission types, such as anti-loosening bolts for DCTs or lightweight fasteners for CVTs. Precision cold heading and thread rolling ensure high dimensional accuracy and reliable fit for automated assembly. All fasteners undergo torque, fatigue, and full dimensional inspection to ensure batch consistency.

We provide integrated fastening kit services, delivering complete gearbox bolt kits based on transmission blueprints for one-stop procurement. With a monthly production capacity exceeding 1.2 million pieces and a dedicated R&D team for rapid customization, we ensure IATF 16949-certified quality with full material traceability and performance reports. Our precise customization, reliable quality, and efficient delivery provide comprehensive support to enhance the competitiveness of transmission products.