plural of drill string

A column of drill pipe on a drilling rig, which transmits drilling fluid and torque to the drill bit.

plural of ratchet drill

A tool for drilling holes, having the bit mounted in a stock and rotated by a ratchet wheel and ratchet lever.

plural of churn drill

A drill worked by hand, not struck with a hammer.

plural of bow drill

A simple rotational hand-operated tool of prehistoric origin, used as a fire drill for ignition, or for other drilling tasks such as woodwork and dentistry.

A technique for boring holes by means of tools attached to a rope and alternately lifted and lowered.

(informal) To be acquainted with the normal process or procedure of a given activity or situation; to be familiar with how something is done.