part of the apparatus of a pit-shaft boring-rod.

Mining. A metal attachment by means of which a rope is connected to a set of boring rods, so enabling them to be lifted. Now rare.

(a) Engineering a graduated metal disc used to support a workpiece to enable the operator to drill or cut at exact angular intervals about an…

(a) a spiral tool for withdrawing wads or charges from guns; (b) Mining (see quot. 1881).

technical. (See quots.)

An attachment for a boring rod used to scatter the detritus produced around a hole as it is bored. Obsolete. rare.

Oil Industry. A long, tapered steel wedge which can be placed at the bottom of a hole to cause the drilling bit to deviate sideways, e.g. in…