8515.39.00.20 - AC transformer type

This HTS category, 8515.39.00.20, specifically classifies AC transformer type machines and apparatus designed for arc welding of metals. These devices utilize alternating current and a transformer to step down voltage and increase current, creating the electrical arc necessary for joining metal workpieces. The classification is for the welding apparatus itself, not consumables like welding rods or wire.

This subcategory is distinguished from its sibling, 8515.39.00.40, which covers "Other" non-rotating type welding machines. While both fall under the broader "Other" category for non-rotating arc welding apparatus, 8515.39.00.20 is exclusively for those employing AC transformer technology. If an arc welding machine does not use AC transformer principles (e.g., inverter-based machines or DC generators), it would be classified under the sibling category.

As this is a leaf node within the HTS, there are no further subcategories. The classification is therefore specific to AC transformer type arc welding machines that are not capable of cutting and are of a non-rotating type. The primary distinguishing factor for inclusion here is the fundamental AC transformer operating principle for generating the welding arc.