Actually it was quite a simple human powered job. The blade was placed in a jig with the tang upright. The guard was slipped on and spacers if needed. A few leather washers which were pre-stamped with the tang cutlout and closely following the maximum outside diameter were installed. A piece of hollow steel, much like a pipe, was slipped over the tang and given a few strikes with a mallet. A few more were installed and whacked again. So on and so forth until the end ofthe tang. A pommel was placed on and the tang pinned in place on pinned tangs or riveted (Peened) if a peened tang. The leather would swell back into place tightening the handle. Initially handles were all hand ground on a wheel. When higher production dictated a machine was produced to do it for the hafters. It worked much like a gunstock blanking machine following a pattern. The grooves would then be brooched like the Mark 2 or the M3. This was when production was needed fast. So companies continued to used large and small washers to make their grooves. These are apparent when you study the knife. The sharp edges on the M3 handles were made by using larger and smaller washers while the grooves with a radius edge were cut in.
