Forming holes in work pieces - explosively with lead bullet

摘要

Holes are made explosively in a work piece without the piston passing through the hole. The work piece in the form of a disc is positioned over a die iwth a central hole that broadens out from top to bottom. The disc is held in position by a block of metal that fits round the die and has a vertical central bell-mounted hole concentric with the hole in the die. The firing piece is positioned vertically over the mouth of this block and a bullet is fired to penetrate the work piece. The nose of the bullet is made of material such as lead which plastically deforms on striking the work piece. The lead can be removed afterwards by melting.