Rigid Metal Conduit
The procedures for making the different types of
bends discussed thus far have all been with a one-shot
bender. The same bends can be made with rigid conduit.
Ahickey bender can be used on rigid metal conduit also
although the procedures are slightly different. For
instance, to make a 90-degree bend in 1/2-inch rigid
metal conduit, you should take the steps shown in figure
5-50. Let us say you need a 20-inch stub-up at the end of
the 1/2-inch stick of rigid conduit. The steps for
bending with a hickey are as follows:
Mark off 20 inches from the end of the conduit.
Determine the take-up for 1/2-inch rigid
conduit. (See table 5-2.)
Make a second mark 6 inches back toward the
end of the conduit.
Place the hickey at the second mark and pull
about 30 degrees of bend.
Move the bender toward the 20-inch mark about
2 inches. Pull another 30 degrees of bend.
Move the bender to where the heel of the bender
is on the 20-inch mark and complete the 90-
Figure 5-50.Bending a 90 with a hickey.
Figure 5-51.Bending with a hickey using small bites.
Since the hickey bender does not usually have
degree markings on it, you have to estimate the amount
of bend you are making with each bite. Small bites, as
shown in figure 5-51, reduce the possibility of crimping
or kinking the conduit.
Mechanical benders are designed to bend conduits
using a built-in ratchet for fast, no kink, bends.
Depending on the make and model, they are portable
and easy to use. Equipped with different shoe sizes,
they will bend EMT conduit from 3/4 inch through 2
inch, rigid and aluminum conduit 1/2 through 1 1/2 and
IMC 1/2 through 1 1/4. Minimum stub lengths and
take-up deductible inches vary from the hand benders
just discussed. While the bending principles are the
same, you will need to check with the manufacturers
directions and bending charts.
In previous sections we have discussed types of
conduits and the cutting, threading, and bending of
conduit. Now, we will cover the requirements for
installing the different types of conduit and how
conductors should be pulled into them.
Several general requirements apply to all types of
conduit installation: All raceways must be installed as a
complete system before any conductors are pulled into
them. In other words, the run of conduit, as described
previously, including conduit, fitting, and supports,
must be complete before the conductors are installed. A
run of conduit should be as straight and direct as
possible. When a number of conduit runs are to be
installed parallel and adjacent to each other, you should
install them all at the same time. The minimum-sized
raceway that can be installed generally is 1/2-inch
electrical trade size. Specific exceptions to this rule