Drawn-down. Decreased in diameter, width or thickness, by forging or swaging.

Drawn-out. Increased in length, by forging or swaging.

Drift. A tool that cuts the walls of a hole while it is driven through by hammer blows.

Drift-pin. A taper pin that is used by boiler makers to drive through holes that do not come fair, or match properly.

Drill. A tool to pierce holes.

Drill-chuck. A chuck used to hold drills.

Drilling-machine. A machine for drilling holes in metal.

Driver. 1. A device for driving work in the lathe and sometimes called a dog or carrier. 2. A gear wheel which drives another.

Drop-hammer. A forging or stamping hammer which is lifted by power and let fall of its own weight.

Drunken thread. A screw thread that is not a true spiral, but is waved in its course.