screw-tap

Definitions

noun A tool for cutting screw-threads on the inside of pipes, or making interior screw-threads of any form. It is the reverse of the external screw-cutter, or screw-plate. Compare plug-tap and taper-tap.

Sorry, no etymologies found.

At the word "Stand by to dismount!" the Quarter-Gunner of the division on the deck above that in which the gun is to be dismounted removes the screw-tap, and stands ready to place the washer, key and un-key the bolt of the breech-purchase block.

Ordnance Instructions for the United States Navy. 1866. Fourth edition.
But as it is desirable that every division on the gun-deck should be exercised in mounting and dismounting its guns, a hole may be made in the deck above each division and bouched with a composition screw-tap.

Ordnance Instructions for the United States Navy. 1866. Fourth edition.