In machining where did the term hemstitching come from?

"hem" is "the edge, border, or margin of anything"(Webster); "stich", from the Greek "stichos", is a single line of anything with multiple lines, such as, a row or line of verse, of an army, or a line of contour. "hem stich es" is multiple lines of a margin or contour (noun). "Hemstich ing" is the act of creating hemstiches. In German, the same root yields steigen, to step, to mount. ("Hemsti t ch" is a method of sewing cloth.)