bars of tool steel (fig. 1-41). They generally range in
size up to 3/4 inch. When using the Allen-type wrench,
make sure you use the correct size to prevent rounding
or spreading the head of the screw. A snug fit within the
recessed head of the screw is an indication that you
have the correct size.
The Bristol wrench is made from round stock. It is
also L-shaped, but one end is fluted to fit the flutes or
little splines in the Bristol setscrew (fig. 1-41).
SAFETY RULES FOR WRENCHES
There are a few basic rules that you should keep in
mind when using wrenches. They are as follows:
Always use a wrench that fits the nut properly.
Keep wrenches clean and free from oil.
Otherwise they may slip, resulting in possible
serious injury to you or damage to the work.
Do not increase the leverage of a wrench by
placing a pipe over the handle. Increased
leverage may damage the wrench or the work.
Provide some sort of kit or case for all wrenches.
Return them to the case at the completion of
each job. This saves time and trouble and aids
selection of tools for the next job. Most
important, it eliminates the possibility of leaving
them where they can cause injury to personnel or
damage to equipment.
Determine which way a nut should be turned
before trying to loosen it. Most nuts are turned
counterclockwise for removal. This may seem
obvious, but even experienced people have been
tightening direction when they wanted to loosen
Learn to select your wrenches to fit the type of
work you are doing. If you are not familiar with
these wrenches, make arrangements to visit a
shop that has most of them, and get acquainted.
Identify the different types of wrenches.
Describe the uses of different types of
List the safety precautions that apply to
LEARNING OBJECTIVES: Identify the
different types of pliers. Describe the uses of
different types of pliers. Describe the proper
care of pliers.
Pliers are made in many styles and sizes and are
used to perform many different operations. Pliers are
used for cutting purposes, as well as holding and
gripping small articles in situations where it may be
inconvenient or impossible to use hands. Figure 1-42
shows several different kinds.
Figure 1-41.Allen- and Bristol-type wrenches.