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 differ-
ent types of wrenches. Each type has its own use. By
using the properwrench 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
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.
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 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.
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.
25-2
