To put a bend into conduit, the method depends on which end you need your measurement from… A or B ( fig 1 )
To bend from end B, you simply line up the measured mark with the outside of the former.. ( fig 2 )
To bend from end A is a little harder and requires a sacrificial piece of conduit (SPC) to obtain the required info..
Measure 500mm from end A of the SPC, place the mark at the back edge of the former ( fig 3 ) and bend to 90 degrees..
Now measure from end A to the top of the former ( fig 4 ) and this will be less than the 500mm..
The difference ( X ) is the measurement you need to add to your required measurement which you then line up with the back of the former ( fig 5 )
If you are working with an old bender that is not your own, you may find it has several marks drawn or notched into the former where someone has figured out that distance ( X ) in the past.. it’s best to not use this as it’s often subjective to the person doing the bending..
It may also be that the mark made is for bending to the midline of the bend or the inside of it..
From end A - Subtract half the diameter of the conduit from your measurement.
From end B - Add half the diameter of the conduit to your measurement.
From end A - Subtract the diameter of the conduit from your measurement.
From end B - Add the diameter of the conduit to your measurement.