Heading 7301 captures angles, shapes, and sections that are produced by welding rather than by hot-rolling in a single continuous pass. Hot-rolled structural sections — I-beams, H-piles, channels — are classified in the heading covering hot-rolled profiles of iron or steel. If a section is assembled by welding plates or strips together, it belongs in 7301 regardless of its final shape.

No. The subheading covers sheet piling whether or not it is drilled, punched, or made from assembled elements, and it does not require a specific interlocking profile. However, the product must be designed for use as piling — driven into the ground to retain soil or water — rather than as a general structural plate or section.