TM 9-243
TYPES AND USES
A wrench is a tool specially designed to tighten or
loosen nuts, bolts, studs, and pipes. Wrenches are
forged from steel alloy to prevent breakage. There are
many different types of wrenches. Each type has its
own use. By using the proper wrench for the task to be
done, you will not break the wrench, damage the
equipment, or cause personal injury. The following
section is intended to give you information on the
different wrench types.
OPEN-END WRENCHES
All open-end wrenches have open jaws on one or both
ends of the wrench. Most jaw openings are offset from
the shank portion of the wrench by 15 degrees. The
wrench length is determined by the size of the jaw
opening. Some of the more common types of open-end
wrenches and their uses are listed below.
The engineer's single open-end wrench has a long
smooth shank providing the user with a better gripping
surface. It is used to reach behind or below blind
surfaces.
The engineer's double open-end wrench has different
size openings on each end. This type of an
arrangement permits a smaller number of wrenches to
complete a set. The engineer's double open-end
wrench is also used to reach behind or below blind
surfaces.
The construction wrench combines the open-end jaw
with a long tapered shank providing a wrench/alignment
punch combination. The construction wrench is used in
the building trades and on heavy objects which require
alignment before fastening.
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