Chapter 4 Wiring Systems
85
Reaming conduit
The ends of a length of conduit must be
smooth to prevent any damage to the wire’s
insulation. After cutting the conduit, use a
reamer, round fi le, or a deburring tool to remove
the burrs. See Figure 4-17.
Bending metallic conduit
The purpose of bending conduit is to route it
around corners and over obstructions. There are
numerous special manufactured fi ttings avail-
able that could be used to achieve similar routing,
but fi eld bends are preferred. A fi eld bend is a
bend that is made on the construction site. This
generally saves time and is far more economical
than installing fi ttings.
Most bends in EMT are made with a conduit
bender. Always use the correct size bender
for the conduit you are bending. This tool is
designed to create a bend with the proper bend
radius. The NEC lists the minimum radius of
conduit bends in Chapter 9, Table 2.
Typical bends include stub (also known as
stub-up), back-to-back, offset, and saddle. The
following sections will help you make these
fundamental bends. Bending conduit is an
important skill you can master with practice.
A pipe reamer mounted in a brace will quickly remove any burrs.
Insert the reamer into the conduit end and rotate the reamer.
Burrs may be removed with metal files. Use a flat file to remove any burrs on
the outside of the conduit. Slide a round file in and out at a slight angle while
rotating the conduit.
A deburring tool designed for EMT is available. Insert the
tool into the end of the conduit and rotate the tool. The
deburring tool will work on 1/2″, 3/4″, and 1″ trade size EMT.
Figure 4-17. The burr created by cutting must be removed, or it may damage the insulation when pulling wires
through the conduit.