Removing the heads of rivets with a cutting torch and a special tip which delivers oxygen to the rivet head at very low velocity.
The rivet head is preheated with flames surrounding a very large oxygen orifice. When the rivet head is red hot, the oxygen valve is opened and the central portion of the rivet head is burned up, leaving the external ring and a cup-shaped end to the shank. The remainder of the rivet can then be backed out without damaging the sheet.