NOTE: After you cut the first piece in a series,
measure it to make sure that the stop is accurately set.
Throatless Shears
Throatless shears are constructed so sheets of any
length may be cut and the metal turned in any direction
during the cutting operation. See figure 4-18. Irregular
lines can be followed or notches made without
Figure 4-19.--18-guage Unishear.
distorting the metal. Throatless shears are an adaptation
of heavy handshears or snips in which the handles are
This tool might be called power-operated, com-
removed, one blade secured to a base, and a long lever
bination snips. It has two short blades. The lower blade
attached to the tip of the movable blade. The
is held in a fixed position. The upper blade moves up
heavy-duty throatless shears are capable of cutting
and down in short strokes at a high rate of speed. Its
stainless steel up to 0.083 of an inch thick.
chewing motion is the basis for the widely used
nickname of this power tool--"nibblers." Figure 4-19
Hand Bench Shears
shows an 18-gauge Unishear.
The hand bench shears operate similar to a paper
The cutting blades are easily removed for
cutter. They have one fixed blade and a movable blade,
sharpening and replacement. The machine will cut as
hinged at the back. They are similar to the throatless
fast as it can be fed, up to 15 feet per minute. This is a
shears except the blades are straight and used only for
ruggedly constructed machine; but for satisfactory
straight cutting. Some bench shears have a punching
performance, you must give it the best of care. It should
attachment on the end of the frame opposite the
be kept cleaned and oiled at all times.
shearing blades. This attachment is used to punch holes
Hand-Operated Turret Punch
in metal sheets.
To cut stock that is narrower in width than the
A hand-operated turret punch is shown in figure
length of the blades, the lever of the shears can be
4-20. Twelve mated punches and dies are mounted in a
pulled all the way down. When you are cutting larger
rotating turret. Stamped on the front of each die block is
pieces, a series of short bites should be made.
the size of hole it will punch, as well as the thickness of
the material it will accommodate. When you are
NOTE: Complete closing of the blade tends to tear
punching stainless steel or other alloys, you must
the sheet at the end of each cut.
remember that these capacities are for mild steel.
Unishear
Unishear is a trade name for a type of portable
power shears. It is used for cutting curves and notches
as well as straight-line cutting.
Figure 4-18.--Throatless shears.
Figure 4-20.--Hand-operated turret punch.
4-11
