Machining Fundamentals 612
fixed-bed milling machine: A type of milling
machine that is characterized by very rigid
worktable construction and support. The
worktable moves only in a longitudinal (back
and forth/X-axis) direction, and can vary in
length. Vertical (up and down/Z-axis) and
cross (in and out/Y-axis) movements are
obtained by moving the cutter head. (Ch. 18)
fixture: A device for holding work rigidly
while machining operations are performed. It
does not guide the cutting tool. (Ch. 9)
flatness: A measure of the variation of a
surface perpendicular to its plane. (Ch. 4)
flexible-back blade: A blade used on metal
cutting saws when safety requirements
demand a shatterproof tool. These blades
are also used for cutting odd-shaped work if
there is a possibility of the work coming loose
in the vise. (Ch. 11)
flexible manufacturing system (FMS): A
manufacturing system with computer-
controlled machinery and adaptive tooling,
which allows the system to be quickly
adapted to changes in the product or the
manufacturing process. Also called computer
integrated manufacturing. (Ch. 26)
flutes: Two or more spiral grooves machined
into a cutting tool to form the cutting edges
of the drill point, facilitate easy chip removal,
and to permit cutting fl uid to reach the
cutting point. (Ch. 12)
follower rest: Similar to a steady rest except
it provides support directly in back of the
cutting tool and follows along during the cut.
Compare with steady rest. (Ch. 15)
foot-pound (ft·lb): The US Conventional
measurement unit for torque. (Ch. 7)
form geometric tolerances: Tolerances that
control the straightness, fl atness, circularity,
or cylindricity of a geometric shape. (Ch. 4)
form grinding: A cutting operation in which
the grinding wheel is shaped to produce the
required contour on the work. (Ch. 20)
friction saw: A metal-cutting tool with a blade
that may or may not have teeth. The saw
operates at very high speeds (20,000 surface
feet or 6000 meters per minute) and actually
melts its way through the metal. (Ch. 11)
Fused Deposition Modeling (FDM): A rapid
prototyping technique that produces three-
dimensional objects based on CAD-generated
solid or surface models. A temperature-
controlled head extrudes thermoplastic
material layer by layer. (Ch. 26)
G
gage blocks: Precisely made steel blocks used
by industry as a standard of measurement.
They are made in a range of sizes and
with a dimensional accuracy of ± 0.000002
(two millionths) inch, with a fl atness and
parallelism of ±0.000003 (three millionths)
inch. Also known as “Jo-blocks.” (Ch. 5)
gaging: To check parts with various gages
to determine whether the pieces are made
within specifi ed tolerances. (Ch. 5)
gang milling: Using two or more milling
cutters to machine several surfaces at one
time. (Ch. 19)
gaseous fluid: A type of cutting fl uid.
Compressed air is the most commonly used.
(Ch. 10)
G-codes: Preparatory codes in the ANSI/EIA
274D code format that is used to program
CNC machines. (Ch. 23)
geometric dimensioning and tolerancing
(GDT): The control of the size of the features
of a part and the allowances (either oversize
or undersize) to achieve interchangeable
manufacturing. (Ch. 4)