196 Agricultural Mechanics and Technology Systems
Copyright Goodheart-Willcox Co., Inc.
based on the diameter of the pipe. Modifi ed sets of
rollers and mandrels are available for bending square
tubing and angle iron.
Cutting Tools
Power saws and other power cutting tools are
machines that use blades (or other attachments)
to separate or shape materials. Some blades and
attachments can be readily sharpened, while others
must be replaced when dulled or damaged from use.
Power cutting tools may be stationary or portable. The
most common power source for this family of tools is
an electric motor, but other methods are also used.
Cutting Tool Rules
When using any type of power cutting tool, observe the power tool
safety rules described earlier and these general safety precautions:
• Unplug or disconnect the power supply before
changing blades or bits.
• Allow the cutting tool or machine to reach full
operating speed before making contact with the
work material.
• Allow the saw to determine the speed of the cut.
Do not force the blade into the work or the work
into the blade.
• Let the cutting tool or machine come to a complete
stop before retrieving the cut parts or pieces.
Circular Saws
Circular saws are portable power saws originally
designed for cutting lumber. As the name implies,
the blade of a circular saw is round and ranges in size
from 3 1/2″ to over 10 1/2″. The diameter of the blade
determines the capacity of the saw, or the thickest
lumber it is capable of cutting through. The most
common saw size drives a 7 1/2″ blade and is well-
suited to cutting 2″ lumber and 3/4″ plywood.
Figure 8-23 shows the two basic circular saw types
that are available, the sidewinder and the worm drive.
The sidewinder—the most common type—uses an in-
line, spur-gear motor that sits at a right angle to the
face of the blade, and the handle is mounted on the
top of the saw. Worm-gear-driven saws use a gearbox
to transfer motor motion 90° to the blade and have the
handle mounted at the rear of the saw.
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Figure 8-21. Cribbing, a method of using stacked
timbers to support a load, is a very secure method
of supporting heavy objects during service or
construction.
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Figure 8-22. This hydraulically powered ironworker
is capable of many functions needed for forming
steel parts. It will shear, notch, punch, and bend
many different types of metal.