3-Point Saddle Bend
22.5° Center Saddle Bend
Everything for a 22.5 degree 3-point saddle: the center-to-outer multiplier, the shrink, a worked example, and the calculator, all from the same math your bender uses.
The 22.5° Saddle Numbers
| Center bend / outer bends | 22.5° / 11.25° |
| Center-to-outer multiplier (applied / exact 1/sin) | 5.1258 / 5.13 |
| Shrink per inch of depth | 0.0985″ |
| 3″ saddle: center to each outer mark | 15.38″ |
| 3″ saddle: shrink to shift the center | 0.3″ |
Distance from center to each outer mark = saddle depth × 5.1258, which is what the calculator applies (the exact 1/sin of the 11.25° outer angle; no bender saddle table we hold prints a 22.5° center row). Shrink = depth × 0.0985″. Center bend 22.5 degrees, both outer bends 11.25 degrees.
The calculator and its 3D show the centerline peak those marks reach once the center arc at the NEC Chapter 9, Table 2 radius is counted, which sits below the depth you enter on every saddle: 2.92″ for the 3″ example in 1/2″ EMT, so enter about 3.08″ there for a 3″ peak. The calculator prints the depth to enter for the peak you need.
The standard shrink chart lists constants at 10°, 22.5°, 30°, 45° and 60°, and publishes none for the 11.25° outer bends this saddle uses. Rather than round to a nearby fraction, the 0.0985″ above is computed from the bend geometry (tan of half the outer angle), which is exactly what the calculator below uses. On a saddle this shallow the shrink is small enough that most techs ignore it.
Calculate Your 22.5° Saddle
The calculator opens in 3-point saddle mode on the worked example, 3″ entered at a 22.5° center (the peak that depth reaches is given above). Enter your own saddle depth for the exact mark spacing and shrink.
Frequently Asked Questions
What is the multiplier for a 22.5 degree saddle?
The center-to-outer multiplier for a 22.5 degree 3-point saddle is 5.1258, which is what this calculator applies (the exact 1/sin of the 11.25° outer angle; no bender saddle table we hold prints a 22.5° center row). The center bend is the full 22.5 degrees and the two outer bends are half that, 11.25 degrees. Multiply the saddle depth by the multiplier to get the distance from the center mark to each outer mark. For a 3 inch saddle that is 3 x 5.1258 = 15.38 inches.
How much does a 22.5 degree saddle shrink?
A 22.5 degree saddle shrinks 0.0985 inch for every inch of saddle depth. A 3 inch saddle shrinks about 0.3 inches, so shift the center mark toward the free end by that amount before bending so the saddle lands centered over the obstruction.
How do you bend a 22.5 degree 3-point saddle?
Find the center of the obstruction and mark it on the conduit, then shift that mark 0.3 inches (the shrink for a 3 inch saddle) toward the free end. Bend the center mark to the full 22.5 degrees. Measure 15.38 inches (for a 3 inch saddle) to each side of the center and mark the outer bends. Rotate the conduit 180 degrees and bend each outer mark to 11.25 degrees. The three bends lift the conduit up and back down over the obstruction.
When should I use a 22.5 degree saddle?
A 22.5 degree saddle is a long, gentle saddle. It shrinks very little (0.0985 inch per inch) and pulls wire easily, but the outer marks sit far apart (multiplier 5.1258), so it needs room. Use it for a shallow obstruction where you have length to work with.
Other Saddle Angles
45° Center Saddle
Multiplier 2.5, shrink 3/16″ per inch, 22.5° outer bends.
30° Center Saddle
Multiplier 3.8637, shrink 0.1317″ per inch, 15° outer bends.
60° Center Saddle
Multiplier 2.0, shrink 1/4″ per inch, 30° outer bends.
Saddle Calculator + All Angles
3-point and 4-point saddle marks, multipliers, and shrink with the calculator.