Mangle-wheel. A gear wheel whose teeth are so arranged that the wheel is reciprocated back and forth on its centre, and does not make a full revolution.

Marking-gauge. A tool used by wood-workers to draw a line upon work.

Master-tap. A standard tap used for producing thread-cutting tools, or kept as a standard of size.

Matched. A board that has a tongue on one edge and a groove on the other so that the edges of the boards will match or be fitted together.

Matching-machine or matcher. A wood-working machine which cuts a groove on one edge and a tongue on the other edge of a board or piece of work.

Measuring-machine. A machine for determining the measurement of a piece.

Micrometer. (mī-krŏm′e-ter). A tool for measuring to minute fractions of an inch.

Mill-file. A single cut file used for filing sheet steel, saw teeth, etc.

Milling-cutter or mill. The cutter or cutting tool used in a milling-machine.

Milling-machine. A machine in which revolving cutters are used to dress the surfaces of metal and cut them to size and shape.