Forming method for annular groove in tube end - has end sidewall formed by bending lip of undercut radially inwards

摘要

The annular groove can be made in the outer surface or in the bore of a tube. It can only be made near the end of the tube. Two steps are made in the wall of the tube by applying pressure to the material. The width and depth of the first step (4) are equal to the width and depth of the final groove required. The second step (5) is so formed that a lip is made at the end of the tube. This lip is spun over to lie against the first step, forming the sidewall of the groove.