Steel Skelp: Ingot to Bloom to Continuous Skelp Mill (National Tube Co., 1921)

Skelp, the steel strip that welded pipe is made from, as National Tube rolled it in 1921: steel ingots are soaked to an even heat, rolled into blooms and sheared hot to length, then reheated and rolled in a continuous mill into long strips sized for one pipe each. For butt-weld pipe the edges are bevelled slightly and one end is trimmed to a point so the welding tongs can start it through the bell. Unknown: the skelp sizes for each pipe; the 'Spellerizing' roll treatment is named but not described. Source: National Tube Co., "National" Modern Welded Pipe (1921), pp. 38-40. Picture: the continuous skelp mill.