2" conduit offset: marks and shrink at every angle

Choosing an angle for a 2" offset

A 2" offset is a small jog: off a wall to a box that sits proud of it, around a strap or a small pipe, or onto a different face of a stud. Length along the run is rarely the problem at this height. Room on the shoe is. The steeper the angle, the closer the two bends, and a real bender’s arcs need somewhere to go.

• 10°: 11 1/2" between bends, 3/16" of shrink. The gentlest bends and the least shrink, for a long open wall or ceiling. It fits every hand-bender shoe from 1/2" to 1-1/4" EMT.
• 22.5°: 5 1/4" between bends, 3/8" of shrink. Half of 45°, with less shrink than 30° and an easier pull. It fits every hand-bender shoe from 1/2" to 1-1/4" EMT.
• 30°: 4" between bends, 9/16" of shrink. The everyday angle: the spacing is simply twice the height. It fits only the 1/2" and 3/4" EMT shoes, is tight on 1" and is too short on 1-1/4".
• 45°: 2 13/16" between bends, 13/16" of shrink. About 29% less length than 30°, for 1/4" more shrink. It is too short on every hand-bender shoe.
• 60°: 2 5/16" between bends, 1 1/8" of shrink. The shortest span and the most shrink, and the hardest on the wire pull. It is too short on every hand-bender shoe.

What the hand-bender table means at 2"

Every bend uses an arc of conduit, and the arc is longer on a bigger shoe. The Greenlee aluminum hand bender's shoes run from a 4 3/16" centerline radius for 1/2" EMT to 9 5/8" for 1-1/4". Two steep bends on a short offset leave little or no straight between the arcs: Too short means they would overlap, and Tight means there is some straight, but less than the shoe needs to grip for the second bend.

At 2", everything up to 22.5° fits all four shoes. 30° fits only the 1/2" and 3/4" EMT shoes, is tight on 1" and is too short on 1-1/4"; 45° and 60° are too short on every hand-bender shoe. If your angle shows Tight or Too short, drop to the next shallower angle.

Worked example: a 2" offset measured from the end

Say the offset has to be complete 24" from the end of the conduit, where an obstruction or a box begins. The conduit climbs on a slant, so it needs more length than the straight run to get there: the shrink. Add it to the measurement for the second mark, then measure back for the first.

1. Measure the height the conduit has to move, from the surface it sits on now to the surface it has to sit on: 2".
2. Measure from the end of the conduit to the face of the obstruction, 24", and add the 9/16" of shrink. Mark the second bend at 24 9/16".
3. Measure 4" back toward the end and mark the first bend at 20 9/16".
4. Bend the first mark to 30°, roll the conduit exactly half a turn, and bend the second mark to 30°. Sight along it to check the two legs are parallel and in one plane.

How a real bender changes the numbers

The tables use the multiplier method, which treats each bend as a sharp corner. A real shoe bends on its centerline radius, so the marks come out a little closer and the offset shrinks a little less. The bigger the radius and the steeper the angle, the bigger the difference. Here is the same 2" offset at 30° on each shoe of the Greenlee aluminum hand bender that can bend it.

On the 1/2" shoe the marks come out 1/16" closer than the chart and the offset shrinks 1/8" less. On the 1" shoe the marks are still about 1/16" closer, but the shrink is 3/16" less. For a one-off the chart is close enough; where the offset has to land on a mark, use your bender’s own radius.

Mistakes that spoil a 2" offset

• Leaving out the shrink. Marked without it, a 2" offset at 30° finishes 9/16" closer to the end than you measured, and everything past it comes up 9/16" short.
• Trusting the rounded shrink. The trade’s 1/4" per inch gives 1/2" at 30°, against the exact 9/16": 1/16" short at this height.
• Measuring to the wrong place. The height is how far the conduit has to move, the same as center to center, not to the far side of the obstruction.
• Rolling more or less than half a turn between the bends, which leaves a dogleg. Draw a line along the top of the conduit before the first bend and keep it on top for the second.
• Going steep to save room. At 45° the bends of a 2" offset are only 2 13/16" apart, which no hand-bender shoe can make.