grooves, a surface adapted to grasping cylindrical
objects.
GROOVE-JOINT PLIERS
Groove-joint pliers (fig. 1-46) are another version
of water-pump pliers and are easily identified by the
extra-long handles, which make them a very powerful
gripping tool. They are shaped approximately the same
as the pliers just described, but the jaw opening
adjustment is effected differently. Groove-joint pliers
have grooves on one jaw and lands on the other. The
adjustment is effected by changing the position of the
grooves and lands. The groove-joint pliers are less
likely to slip from the adjustment setting when gripping
an object. The groove-joint pliers will only be used
where it is impossible to use a more adapted wrench or
holding device. Many nuts and bolts and surrounding
parts have been damaged by improper use of
groove-joint pliers.
DIAGONAL PLIERS
Diagonal cutting pliers (fig. 1-42) are used for
cutting small, light material, such as wire and cotter
pins in areas that are inaccessible to the larger cutting
tools. Also, since they are designed for cutting only,
larger objects can be cut than with the slip-joint pliers.
Because the cutting edges are diagonally offset
approximately 15 degrees, diagonal pliers are adapted
to cutting small objects flush with a surface. The inner
jaw surface is a diagonal straight cutting edge.
Diagonal pliers should never be used to hold objects,
because they exert a greater shearing force than other
types of pliers of a similar size. The sizes of the
diagonal cutting pliers are designated by the overall
length of the pliers.
SIDE-CUTTING PLIERS
Side-cutting pliers (sidecutters) are principally
used for holding, bending, and cutting thin materials or
small gauge wire. Sidecutters vary in size and are
designated by their overall length. The jaws are
hollowed out on one side just forward of the pivot point
of the pliers. Opposite the hollowed out portion of the
jaws are the cutting edges (fig. 1-42).
When holding or bending light metal surfaces, the
jaw tips are used to grasp the object. When holding
wire, grasp it as near one end as possible because the
jaws will mar the wire. To cut small-diameter wire, the
side-cutting edge of the jaws near the pivot is used.
Never use sidecutters to grasp large objects, tighten
nuts, or bend heavy gauge metal, since such operations
will spring the jaws.
Sidecutters are often called electrician or lineman
pliers.
They
are
used
extensively
for
stripping
insulation from wire and for twisting wire when
making a splice.
DUCKBILL PLIERS
Duckbill pliers (fig. 1-47, view A) have long wide
jaws and slender handles. Duckbills are used in
confined areas where the fingers cannot be used. The
jaw faces of the pliers are scored to aid in holding an
item securely. Duckbills are ideal for twisting the safety
wire used in securing nuts, bolts, and screws.
1-29
Figure 1-46.—Groove-joint pliers.
Figure 1-47.—Pliers; (A) duckbill, (B) needle-nose, and
(C) wire twister.
