Manufacturing Process

Once our customer care team has identified your specific requirements for goods to be manufactured they will generate a works order which our production department then picks up.

The Production Manager selects the appropriate specification sheet from our library of over 6,000 and issues this to the shop floor in the form of a job card. This card contains a unique job reference number enabling total traceability throughout the entire production process. During each process, this job card is signed off by each member of production before it is passed to the next stage.

A typical leaf spring production process is as follows;

  • Spring steel to BS970 is sheared or sawn to the required length.
  • Parabolic springs begin life as a piece of spring steel of equal thickness and are then taper rolled as instructed by the operator.
  • The ends of the main leaves are heated and the eyes of the springs are formed as well as any leaves which wrap around the spring eye.
  • Drilling is carried out on each leaf for springs fitted together with a centre bolt and any holes which house interleaf pads are drilled at this point.
  • Any required nibbing, slotting, punching or spearing of the leaves is carried out next once the leaves have reached the necessary temperature.
  • The leaves are then sent for heat treatment. Each leaf is placed into the furnace and heated to between 950 and 1050°C.
  • Using a two-man team, each leaf is taken out of the furnace and bent to the required shape.
  • The leaves are then quenched in oil and once drained they are placed on the tempering mattress.
  • The leaves are slowly carried through the tempering furnace at a temperature of between 500 and 550°C to achieve the correct Brinell hardness reading.
  • The required components such as bushes, clips, centre bolts etc. are added in the assembly shop and the spring is completed.
  • The spring is then coated in a protective black paint and once dry, the label including the works order number, customer and part number is added.
  • The spring undergoes a final quality inspection prior to being despatched or collected.

Locomotive springs follow a similar production route and inspection process but with the inclusion of a mandatory load test and test certificate.