Offset multipliers and shrink
Distance between bend marks = offset depth × multiplier (the multiplier is 1 ÷ sin of the angle). Shrink is how much shorter the run gets, and it's added to your measurement to the obstruction.
| Bend angle | Multiplier | Shrink per inch of depth |
|---|---|---|
| 10° | 6.0 | 1/16 in |
| 22½° | 2.6 | 3/16 in |
| 30° | 2.0 | 1/4 in |
| 45° | 1.4 | 3/8 in |
| 60° | 1.2 | 1/2 in |
3-point saddle
- Centre bend 45°, two outer bends 22½° each.
- Mark the centre of the obstruction. Place the outer marks 2½ in from centre for every inch of saddle depth.
- Shrink is about 3/16 in per inch of depth. Move the centre mark ahead by that amount.
90° stub-up
Measure the stub height, subtract the bender's take-up (deduct) for that conduit size, and line the mark up with the bender's arrow. Take-up is marked on most benders. Check yours rather than using a chart, because it varies by brand and conduit type.
⚠️ Reference only. Always verify against the manufacturer's specs, your jurisdiction's code and your site's procedures.