Automatic wire feed is a standard feature of virtually all MIG/MAG welders and by itself does not typically elevate a machine to 'partly automatic' status for classification purposes. The automation criterion generally requires that the machine automatically controls the movement of the torch or workpiece through the weld path, not merely the consumable feed. A hand-held MIG welder with wire feed would normally be classified under a different heading for manual arc welding equipment, not under 851531.

Plasma arc welding machines, which use a plasma arc to join metals, are classified under heading 8515 (electric welding machinery). Plasma arc cutting machines, which use a plasma arc to sever metal, are classified under heading 8456 (machine tools operating by plasma arc processes) or heading 8467/8515 depending on design. The intended function — joining versus cutting — and the machine's design features are the primary classification determinants. Importers of combination plasma cutting-and-welding systems should evaluate the principal function under GRI 3.