Record each spring’s wire lot, load test and setting from coiling to packing.

Spring makers coil wire into compression, extension and torsion springs, then grind, stress relieve, set, shot peen and test them. Wire diameter, coil count and free length are easy to measure with a caliper and a counter at the bench, long before the springs go for heat treatment. The load at working length is what the customer pays for. It is easy to miss.

Production control for spring shops keeps the wire coil lot, the coiler programme, the oven batch and the load test result together for each order. Drawing revision, wire grade and finish are held on the part. Share a drawing with your requirements.

A maker of switches, seats, valves or machines sends a drawing with wire diameter, material, outside diameter, free length, number of active coils and a load at a stated height. You quote from wire weight, coiling time, grinding of ends, heat treatment and testing. Wire arrives on coils with a mill certificate and is loaded on a CNC coiling machine, which is set with the first-off springs measured before the run starts.

After coiling, springs go to a stress relief oven in trays. Compression springs may be ground at the ends and pressed solid to set them. Surface finishes such as zinc plating, powder coating or phosphate are often done by an outside process house. Final checks measure free length, load at height and squareness, and the tester reading is written on a tag that travels with the tray to the packing bench. Counted packs go out in boxes or on rods.