Resistance Welding Machines for Metal (N.E.S.)

The determining factor is whether the machine's welding cycle — including electrode pressure, current application, and hold time — is controlled automatically by the machine's own control system. If an operator must manually initiate and control each phase of the weld, the machine is non-automatic and falls under 73734. Technical specifications from the manufacturer, including control system descriptions, are the primary evidence used in this determination.

Portable resistance spot welding guns or tongs that are manually operated and lack an integrated automatic control cycle generally fall under 73734 as non-automatic resistance welding apparatus. However, if the portable gun is designed to be used as part of a larger automated welding system, its classification may follow that of the complete system. The standalone versus integrated-component distinction is key.