Chapter M: M Muntz Metal, Leaded

M

M

Symbol for mega or million (10 ⁶).

M

(italicized): Symbol for (1) moment of force; (2) mutual inductance.

m

Symbol for meter.

m ²

Symbol for square meter.

m ³

(1) Symbol for cubic meter; (2) milli- (10 ^-3).

machinability

A term used to describe the ease with which an engineering material can be machined, worked, or cut. It is based on various factors including rate of metal removal, tool life, surface roughness, and power consumption. Most common metals are rated in terms of machinability using B1112 steel at 100%, as the comparison baseline. By comparison, carbon and chromium steels are rated from about 45 to 60, while aluminum is rated from 300 to 2,000. Generally, as the machinability rating is increased, the cutting speed is also increased.

machinability factor

Also called machininability rating. A percent indicator of the machinability, or ease in machining or cutting various workpiece materials.

See also machinability.

machine bolt

A bolt containing a square head, and unlike the carriage bolt, having no square portion on the shank, and fitted with either a square or hexagonal nut. Machine bolts are machined straight from the point to the head and are usually threaded for about three-fourths of their length. The unthreaded portion is the same diameter as the threaded part. In order to tighten a machine bolt a wrench is put on the head while the nut is held stationary.

machining center

Also called N/C machining center. A...