(b) Strap pipe wrench. The strap pipe wrench (fig 10) is also used to
turn cylindrical parts, but it 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 (fig
10) 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 pipework 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.
(5) Torque wrenches. A torque wrench (fig 11) is used for work requiring a
particular 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 several sizes. They may have a 1/4-, 1/2-, or 3/4-inch
square drive to receive socket wrenches and the capacity may range up to 600 foot-
(6) Spanner wrenches.
(a) Fixed spanner wrenches. Fixed spanner wrenches (fig 12) are used to
and parts which have holes or slots for insertion of the wrench pins or lugs. Each
of this type spanner wrench is designed for a particular job.
(b) Adjustable spanner wrenches. An adjustable face spanner wrench (fig
12) has two legs joined together with a pivot pin. The legs can be opened and
closed, thus allowing the pins at the end of the legs to fit the various distances
between holes found in many types of cover plates and plugs. Another type of
adjustable spanner wrench is shaped like a hook, called an adjustable hook spanner
wrench. The position of the hook can be adjusted to fit different size couplings
and other parts.