USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
(c) Clamp Pliers and Vise Grip Wrench. The clamp pliers and vise
grip wrench (figure 21 on the previous page) has one movable jaw and one
stationary jaw. The movable jaw is adjusted by an adjusting screw in the
base of the stationary jaw handle. The movable jaw can be clamped around a
nut or bolt after setting the jaw to the desired size. This type wrench is
issued in two sizes; 1 1/8 inch jaw opening capacity and 7 inches long, and
1 1/4 inch capacity and 10 inches long.
(a) Adjustable Pipe Wrench.
21) has two jaws that are not parallel. The outer jaw, which is adjustable,
is made with a small amount of play which provides a tight grip on the pipe
when the wrench is turned in the direction of the movable jaw. This is the
only wrench which will take a bite on round objects. The jaw always leaves
marks on the work and should never be used on a nut or bolt unless the
corners have been rounded so that it cannot be turned with another type of
(b) Strap Pipe Wrench. The strap pipe wrench (figure 21) is also
used to turn cylindrical parts, but will not mar the work because the strap
serves as jaws. These wrenches are issued in a 1/8 to 2 inch pipe capacity
size and a 1 to 5 inch pipe capacity size.
(c) Adjustable Chain Pipe Wrench.
The adjustable chain pipe
wrench (figure 21) is a long-handled tool with a single jaw and a length of
chain that fits around the pipe to be turned and over the connection at the
end of the jaw. The chain acts as the other jaw. It is used for gripping
rough pipe work on large diameter pipe. These wrenches range in size from
35 to 64 inches long and have a pipe capacity of from 3/4 inch to 12 inches.
(4) Torque Wrenches.
A torque wrench (figure 22 on the following
page) is used for work requiring a specified force (torque) to tighten
bolts, nuts, capscrews, etc., to a desired degree of pressure. A dial or
scale calibrated in foot-pounds indicates the degree of torque placed on the
work. The pointer moves to the right or left of zero, depending on the bolt
(left or right hand threads) being tightened. These wrenches are issued in