Stringent quality control is a priority here at Jones Spings. Once a job has been allocated a spec sheet it is then passed onto the production team as a job card, specification job cards always contain a unique job reference number enabling total traceability throughout the entire manufacturing process.

Spring steel to grade 251 A58 (EN45A) is sheared to the length required by the specification and processed through the required manufacturing operations, including eye forming, drilling, punching, and wrapping.

The leaves are then passed to heat treatment (1,000 - 1,050°C), shaped and oil quenched to give a quenching temperature of no less than 890°C. After draining, they are tempered at 500 - 560°C to give the correct hardness before final adjustment to give correct shape and camber.

On the final assembly line, the required components are added, i.e. bushes, clips, centre bolts, etc. to complete the spring, which is again checked against the specification sheet. The spring is then either painted or finished to the customer's requirements.