Custom Torsion Spring Project for BYD Auto Parts, 580,000 Pcs Bulk Order

Client:BYD

Project Timeline:Feb.2024 — Jun.2024

 Order Quantity:580,000 pcs automotive torsion springs

These torsion springs are used for door actuator assemblies of BYD new energy vehicles. As auto safety-related parts, they need to pass million-cycle torsion fatigue test and salt spray corrosion test under strict auto component standards.

Development started in February 2024. The first 3 batches suffered torque attenuation and surface rust during fatigue test. We switched to AISI 304 stainless steel, optimized torsion arm angle and passivation anti-rust treatment. Totally 7 rounds of durability and high-low temperature cycle tests were finished with the customer lab.

 Samples got PPAP approval in May 2024. 580,000 pcs were mass-produced and delivered in 4 shipments in June, with full dimension, torque and salt spray inspection reports for each batch. No early failure was found after vehicle assembly test. We keep developing more torsion springs for cabin mechanisms and become designated supplier of structural springs for BYD.