Segment bending is a method of bending conduit by making several
small bends to produce one larger bend. The segment bend on this page
illustrates producing a 90º bend by making
a total of 9 bends at
The steps for making a segment bend are:
- Determine the radius of the desired bend.
There are several factors that can determine what the radius of a
bend will be. A radius larger than the radius of a bender's
shoe may be required to meet a job's specifications. Sometimes
the radii of conduit bends on a job are specified to meet a
manufacturer's specification, such as cable used for voice, data, or
video. Larger radii bends are also easier to pull, and put
less strain on the cable being pulled. Larger radii may also
be used to fit conduit around an object that may be in the way, if
the standard bender shoe radius is used. Larger that normal
radii may be required to fit conduit either inside, or around an
object, such as a tank, or a barrel-shaped ceiling.
- Determine the number of segments desired
or required for the completed bend.
The greater the number of segments in a large radius bend, the
smoother the overall bend will be. Job related factors may
determine what radii will be used. If, for example, small EMT
is used on a conveyor system, it is faster to bend with a standard
hand bender. Most hand benders for 1/2" EMT through 1-1/4" EMT
have 10 degree marks. A 90 degree bend for
a conduit could then be made with 9, 10 degree bends.
- Determine the Developed Length of the bend.
Developed length (DL) is the length of conduit that is actually
bent. The formula to calculate the developed length of a bend is:
Developed length (DL) is equal to the centerline radius (R) of the
bend times the angle (A) of the bend times 0.01745.
DL = R x A x 0.01745
The developed length for a 90 degree bend with a 40" radius is
90 x 40 x 0.01745 = 62.82".
DL = 90 x 40 x 0.01745 = 62.82"
To use the segment bending calculator:
- Select the Total angle of the Bend.
- Select the number of bends to use to make the segment bend.
- Select the centerline radius of the bend.
- Select 'Calculate' button.
The angle of the individual segment bends, the
distance between bends, and the Total Length , or Developed Length
of the bends, will be calculated for you.
The length of the bent portion of conduit = Radius x Degree of bend x
For a 90º bend with a centerline radius of 40",
Length = 90 x 40 x 0.0175 = 62.82".
Notice, that as a matter of practicality, the distance between bends must be greater
than the length of each bent segment. If the distance between bends is not greater
than the length of each bent segment, select a lesser number of bends to make, and/or a
different centerline radius.