Pressure springs are a type of hardware component formed in a spiral geometric shape by wire, so the hardening processes for them are somewhat more difficult compared to flat hardware components (such as stamped parts).

Additionally, it is crucial to strictly control the hardening effect on the cross-section of the pressure spring in order to thoroughly understand its resistance to fatigue fracture after use. The hardening of pressure springs generally employs two methods: shot peening hardening and heat treatment hardening.

For processing a batch of pressure springs using shot peening: each pressure spring can be individually transported on a conveyor belt to the shot peening chamber, which is equipped with a series of parallel roller tracks. While being reinforced, the springs roll forward, allowing the high-speed shot stream to pass through the gaps between each coil of the pressure spring and strike the metal surface of the inner coil, which is precisely where the stress on the pressure spring is most concentrated.

Shot peening is one of the best reinforcement methods for suspension springs, and high-stress springs can have their fatigue life increased by more than four times with proper shot peening.