3-Point Saddle Calculator
By Andrew ·
Quick answer
A 3-point saddle is a 45° center bend between two 22.5° outer bends. Put the center mark on the middle of the obstruction and each outer mark about 2.5 times the obstruction height away (the exact figure is 2.613). Each side shrinks about 3/16" per inch of height, and the whole saddle twice that. Over a 4" pipe, the outer marks go about 10" either side.
Calculator
- Results
- Center mark to each outer mark
- 7 13/16" (7.84")
- Center bend angle
- 45°
- Total shrink
- 1 3/16" (1.19")
Worked out the textbook way, from the bend angle alone. BendMate also uses your bender’s radius, deduct and shoe.
Where the three marks go
Each half of a saddle is a small offset: the conduit climbs from an outer bend to the center bend, then comes back down. The center bend is twice the angle of the outer ones, so the two outer bends together cancel it.
outer marks ≈ 2.5 × obstruction height, each side of the center markshrink per side = height × 0.199Worked example: a 3" pipe
- Obstruction height
- 3"
- Center bend
- 45°
- Outer bends
- 22.5°
- Outer marks, trade rule
- 3" × 2.5 = 7 1/2" each side of center
- Outer marks, exact
- 3" × 2.613 = 7 13/16" each side
- Shrink, whole saddle
- about 1 3/16"
- Center mark shift
- about 5/8" further from the end
- Find the middle of the obstruction and mark the conduit there. When you measure from the end, push this mark out by one side of shrink, because the first half of the saddle uses up conduit before it reaches the pipe.
- Measure the outer marks out from the center mark, one each side.
- Bend the center mark to 45°.
- Turn the conduit over and bend each outer mark to 22.5°, with the hook facing the center bend.
- Lay it on a flat surface to check that both ends sit flat and the three bends are in one plane.
Other angle combinations
The rule is always the same: the center bend is twice the outer bends. A flatter saddle needs more room along the run, a steeper one needs less but takes more shrink.
| Center / outer | Outer mark from center | Shrink per side |
|---|---|---|
| 30° / 15° | 3.864 | 0.132 |
| 45° / 22.5° | 2.613 | 0.199 |
| 60° / 30° | 2.000 | 0.268 |
Common saddle mistakes
- Making the outer bends a different angle from each other, which tilts the conduit off its original line.
- Forgetting the half turn, which lays the three bends in two different planes.
- Measuring the height to the middle of the pipe when the conduit has to clear its top.
- Using a 3-point saddle on something wide like a beam or a duct. Its pointed peak will not sit flat across a wide top; use a 4-point saddle.
Saddles and your bender
The center mark has to meet the center-bend notch on your shoe, which is cut for 45° on many hand benders. In BendMate the same math accounts for your bender’s radius and deduct, which shifts the real marks a little from the chart numbers.
Get the marks for your bender
BendMate works this out from your bender’s radius and deduct, flags a bend that won’t work, and shows you every mark.
Common questions
What angles do you use for a 3-point saddle?
A 45° center bend with two 22.5° outer bends is the standard. Any combination works as long as the center bend is twice the outer ones, for example 30° with 15° or 60° with 30°.
How far from the center mark do the outer marks go?
About 2.5 times the obstruction height, each side. For a 3" obstruction that is 7 1/2", or 7 13/16" using the exact 2.613 multiplier.
How much does a 3-point saddle shrink?
About 3/16" per inch of obstruction height on each side, so twice that overall. A 3" saddle shrinks about 1 3/16".
Why does the center mark move?
Measured from the end of the conduit, the first half of the saddle shrinks the conduit before it reaches the pipe. Moving the center mark out by one side of shrink keeps the peak centered on the obstruction.