Machining Fundamentals 606
boring mill: A huge machine capable of
turning and boring work with diameters
as large as 40′ (12 m). Work that is too large
or too heavy to be turned in a horizontal
position is machined on a vertical boring
mill. (Ch. 15)
box annealing: A method of annealing in
which the work is placed into a metal box,
which is then placed into the furnace, heated
to the proper temperature, and allowed
to cool inside the furnace. Keeping the
work inside the box during heating and
cooling prevents the work from scaling or
decarbonizing. (Ch. 29)
Brinell hardness test: A method of measuring
a metal’s resistance to deformation. In this
test, a known load is applied to a metal
through a steel ball of known size. The
hardness reading is based on the diameter
of the impression made by the steel ball.
(Ch. 29)
briquetting: In the powder metallurgy process,
the operation that compresses and forms
metal powder into the desired shape. (Ch. 33)
broach: A long, multitoothed cutting tool with
three kinds of teeth shaped to give a desired
surface: rough, semifi nished, and fi nished.
(Ch. 17)
broaching: A manufacturing process for
machining fl at, round, and contoured
surfaces, both internal and external. A broach
is pushed or pulled across the work, with
each tooth removing only a small portion of
the material. Cutting a keyway is typically a
broaching process. (Ch. 17)
broaching machine: A machine designed to
push or pull a multitoothed cutter across the
work, each tooth of the cutting tool (broach)
removing only a small amount of material.
(Ch. 1)
burnishing: The process of fi nishing a metal
surface by compressing the surface. It is often
done by tumbling the work with steel balls.
(Ch. 17)
bushing: A bearing for a revolving shaft. Also,
a hardened steel tube used on jigs to guide
drills and reamers. (Ch. 9)
C
canned cycle: A set of commands that follows
a prescribed sequence again and again until
the cycle is cancelled. Also called subroutine.
(Ch. 24)
carbon content: The amount of carbon that
a material contains. In reference to steel, it is
measured in percent or points. (Ch. 28)
career: An occupation requiring specialized
training. (Ch. 2)
Cartesian coordinate system: A coordinate
system that specifi es positive (+) and
negative (–) movement along X, Y, and Z
axes; used in CNC programming to specify
movements of the workpiece or tool.
(Ch. 22)
case hardening: A heat treatment process that
creates a hard shell on the surface of low-
carbon steel while leaving the inner core of
the metal unaffected. (Ch. 29)
center finder: A device used in a drilling
machine to position the point to be drilled
directly under the chuck or spindle. Also
known as a “wiggler.” (Ch. 12)
centerless grinding: A technique in which a
workpiece is not supported between centers;
rather, it is positioned on a work support
blade and fed automatically between a
regulating or feed wheel and a grinding
wheel. (Ch. 20)