plural of pin drill

plural of tap drill

plural of traverse drill

A fluid used to aid the drilling of boreholes, serving to provide hydrostatic pressure, to keep the drill bit cool and clean, and to suspend the drill cuttings.

plural of drilling fluid

plural of khaki drill

plural of rock drill

A powerful drill that can cut through stone.

plural of drop-drill

An agricultural device for dropping seed and manure into the soil simultaneously.