Rolled Ring
A ring, a hoop or part of one rolled from flat bar or strip: the length to cut on the neutral line, with the gap for the weld and the flat ends. A ring, a hoop or part of one rolled from flat bar or a strip of plate: the length to cut, measured on the neutral line, with the gap for the weld and the flat ends the rolls leave.
How the rolled ring is developed, with a worked example · Rings and helicals