Several electric resistance welding (ERW) processes are available for ERW steel tube and ERW steel pipe production. While each process has different characteristics, all ERW processes have one thing in common–all of them produce a forged weld.

A forged weld is created by applying a combination of heat and pressure, or forging force, to the weld zone. A successfully forged weld uses the optimum amount of heat, which is normally slightly less than the melting point of the material, and a nearly simultaneous application of circumferential pressure to the section, which forces the heated edges together.

As the name implies, the heat generated by the welding power is a result of the material’s resistance to the flow of electrical current. The pressure comes from rolls that squeeze the tube into its finished shape.

The two main types of ERW processes are high-frequency (HF) and rotary contact wheel.