1. A piece of metal wire twisted at one end to form a guard to keep the explosive in a shothole in place and twisted at the other end to form a guard to hold the tamping in its place.

2. A piece of wood doweling interposed between charges to extend the column of explosive.

3. A device for holding two members at a given distance from each other. Also known as spacer block.

4. The tapered section of a pug joining the barrel to the die; clay is compressed in this section before it issues through the die.