4-Point Saddle Calculator
By Andrew ·
Quick answer
A 4-point saddle is two matching offsets with the obstruction between them, used for anything too wide for a 3-point saddle. Each offset uses height × multiplier between its bends, and the level run across the top equals the obstruction width. Shrink is twice one offset's, so at 30° a 6" tall beam has the marks of each offset 12" apart and about 3 3/16" of shrink.
Calculator
- Results
- Between the bends of each offset
- 6"
- Across the top of the obstruction
- 10"
- Total shrink
- 1 5/8" (1.61")
Worked out the textbook way, from the bend angle alone. BendMate also uses your bender’s radius, deduct and shoe.
Two offsets with a flat between them
Think of the saddle as an offset up, a level stretch over the obstruction, and a mirror-image offset back down. All four bends use the same angle, so the conduit leaves and rejoins its original line parallel.
- Marks 1 to 2: the first offset, height × multiplier apart.
- Marks 2 to 3: the flat across the top, the width of the obstruction.
- Marks 3 to 4: the second offset, the same distance as marks 1 to 2.
shrink = 2 × height × shrink per inchWorked example: 5" high, 14" wide
- Obstruction height
- 5"
- Obstruction width
- 14"
- Angle
- 30°
- Offset marks apart
- 10"
- Mark 1
- 0" (the first bend)
- Mark 2
- 10"
- Mark 3
- 24"
- Mark 4
- 34"
- Shrink
- 5" × 2 × 0.268 = about 2 11/16"
Marks are measured along the conduit from the first bend, as a chart would give them. Add the position of mark 1 from the end of the conduit to every figure.
Choosing the angle
A steeper angle packs the saddle into less length but eats more conduit in shrink. For a tall obstruction, 45° keeps each offset short; for a low one, 30° is easier on the wire.
| Angle | Marks apart | Shrink, whole saddle |
|---|---|---|
| 22.5° | 13 1/16" | 2" |
| 30° | 10" | 2 11/16" |
| 45° | 7 1/16" | 4 1/8" |
| 60° | 5 3/4" | 5 3/4" |
Where a 4-point saddle goes wrong
- Turning the bender the wrong way for marks 3 and 4, so the conduit climbs again instead of coming down.
- Measuring the width along a sloped or rounded top instead of the straight distance across it, which is what the level stretch has to cover.
- Mixing angles between the two offsets, which leaves the far leg off the original line.
- Forgetting that the top must be level; sight along it before it goes in.
Bender effects
Each half is an ordinary offset, so a real shoe makes each pair of marks a little closer than the chart. In BendMate the same math accounts for your bender’s radius and deduct, and flags a saddle whose bends would collide.
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
When should I use a 4-point saddle instead of a 3-point?
Use a 4-point saddle when the obstruction is wider than a pipe, such as a beam, duct or cable tray. A 3-point saddle makes a pointed peak, which is right for a round pipe but does not clear a wide flat top.
How do you find the marks for a 4-point saddle?
Mark the first bend, then the second at height × multiplier from it. The third mark is the obstruction width past the second, and the fourth is another height × multiplier past the third.
How much does a 4-point saddle shrink?
Twice the shrink of one offset of the same height. At 30° that is 0.268" × 2 = 0.536" per inch of height.
Which angle is best for a 4-point saddle?
30° is the usual choice and 45° suits tight spaces. Shallow angles need more room along the run but pull wire easier and shrink less.