How to Bend a 90 and an Offset in Half-Inch EMT

Why this matters

A hand bender is the cheapest tool on the truck and the one that wastes the most material in an apprentice's first month. The waste is rarely bad strength or a bad bender. It is measuring from the wrong reference, forgetting take-up on a 90, forgetting shrink on an offset, or rotating the pipe a few degrees off between the two bends of an offset so it comes out with a dog-leg that will not sit flat on the wall. Each of those has one specific fix, and once a tech knows which mark goes where and why, a stick of 1/2 in EMT turns into a stub or an offset on the first try.

Safety and setup

Cut and ream with eye protection on. Cut with a hacksaw, a tubing cutter or a band saw, and ream every cut end inside and out before it gets a fitting (NEC 358.28, 2023, 2020 where the section moved, as adopted); a burr strips conductor insulation on the pull. A cut-off wheel throws hot metal and sparks, so it gets a face shield over safety glasses and a clear area free of anything combustible.

Bend on a hard, flat, clean floor, not on a tailgate or a pallet. The pipe must stay flat on the floor through the whole pull, and the bender's heel needs a surface that will not let it skid. Keep your foot on the bender's foot pedal with steady pressure; a bender that slips under heavy handle force puts the handle into your face or shin. Bend facing the handle, never with the handle pulled toward your head.

Know your bender's marks. Most 1/2 in EMT hand benders carry an arrow (the take-up reference for a stub-up), a star or similar mark (the back of a 90, for back-to-back measurements), and degree marks or a sight line for common angles. Read the shoe of your own bender; the marks are cast in, and the instructions that came with it name them.

The stub-up 90

Take-up is why the mark is not at the stub height. When you bend a 90, the pipe wraps around the bender's shoe, so the stub that ends up standing vertical is longer than the distance from the arrow to the end. For 1/2 in EMT on a standard hand bender, that difference is 5 in. Subtract it from the stub height and put that mark on the arrow.

1. Measure from the end and mark. For a stub height H, mark at H minus 5 in from the end of the pipe. Draw the mark all the way around the pipe so you can see it from any side.

2. Set the bender. Place the pipe on the floor, the bender's hook on the pipe, and the arrow lined up on the mark, with the stub (the end you measured from) extending out past the bender's hook. Set the bender facing the other way and the take-up no longer lines up with your measurement, so the stub comes out the wrong length.

3. Pull. Steady foot pressure on the pedal, handle drawn back in one smooth motion. Keep the pipe flat on the floor; if it lifts, the bend moves. Go a degree or two past 90, because EMT springs back a little when you release.

4. Check. Stand the stub against a torpedo level for plumb, then measure from the floor to the end.

Back-to-back 90s

When a stick has to turn up at both ends to fit between two points, say from one floor box up a wall and across to the next, the second 90 is measured to its BACK, the outside face of the bend, not to the end of the pipe. That is what the star mark is for: it sits where the back of the finished 90 will fall.

After the first 90, measure from the back of that first bend along the pipe to where the back of the second bend has to land, mark it, and put the mark on the star rather than the arrow, with the bender reversed so the second stub turns the same way as the first. For a 30 in back-to-back on 1/2 in EMT, the mark goes at 30 in from the back of the first 90, on the star. Measure the result outside to outside, and hold it to the same 1/8 in as a stub. Check your bender's instructions for which way the hook faces on the second bend; they differ in how they show it.

The offset

An offset is two equal bends in opposite directions that move the pipe sideways (the offset depth) and send it on parallel to its original line. Two numbers govern it:

The multiplier is geometry, not a bender constant. The slanted section is the hypotenuse of a right triangle whose short side is the offset depth. At 30 degrees the hypotenuse is twice the short side, so marks for a 4 in offset sit 8 in apart. At 45 degrees it is about 1.41 times, so 4 in becomes about 5-5/8 in.

Shrink is the length the offset eats. The slanted section covers less distance along the wall than its own length, so the pipe comes up short by that difference. At 30 degrees that is 8 in of pipe covering about 6.93 in of wall, about 1.07 in lost on a 4 in offset, which the field figure rounds to 1/4 in per inch. At 45 degrees the exact figure is a little over 0.41 in per inch of depth, so the 3/8 in field figure runs light by a little over 1/8 in on a 4 in offset; on a deep 45 degree offset, add a sixteenth or two.

Why the angle choice matters. A 30 degree offset is gentler on the pull and uses less of the 360 degree allowance between pull points (two 30s count as 60 degrees, two 45s as 90; NEC 358.26). A 45 degree offset is shorter, which is why you use it where the obstruction leaves no room for a long slant.

1. Mark. When you are working toward an obstruction from a fixed end, the far mark goes at the distance to the obstruction plus the shrink; the near mark goes one multiplier-distance back toward the fixed end.

2. Draw a straight line along the pipe through both marks. That line is your rotation reference.

3. First bend. Align the near mark with the arrow and bend to the angle using the bender's degree marks or sight line.

4. Rotate exactly 180 degrees. Turn the pipe over so the line drawn along it faces straight up (or straight down) again, then slide the bender to the far mark.

5. Second bend, the same angle, in the opposite direction. Stop at the angle, not past it; overbending one bend is what makes the two runs stop being parallel.

Worked example: a stub and a 4 in offset on one wall

A new box sits low on a block wall, fed from above by a conduit that must clear a 3-1/2 in water pipe running across the wall. The tech needs a 12 in stub-up at one end and, along the wall, a 4 in offset (the 3-1/2 in pipe plus 1/2 in of clearance) that is fully stepped out by the point where the water pipe starts, 30 in from the coupling end of the stick.

 STUB-UP: 12 in, 1/2 in EMT, take-up 5 in
              end of pipe
               |
               |  floor to end = 12 in
               |
 --------------+  <- back of the 90 on the floor
 mark: 12 - 5 = 7 in from the end, on the arrow

 OFFSET: 4 in deep, two 30 deg bends
 coupling end           water pipe starts 30 in out
 |                                  |
 ===========A                       |
   23 in     \  A to B = 8 in       |
              \                     |
               B =====================  4 in out
               31 in = 30 in + 1 in shrink

Stub. 12 in minus 5 in take-up: mark at 7 in from the end, on the arrow, stub end toward the hook. Pulled to just past 90, it measures 12-1/16 in floor to end. 12-1/16 in is within 1/8 in of 12 in, pass.

Offset at 30 degrees. Depth 4 in. Distance between marks: 4 x 2 = 8 in. Shrink: 4 x 1/4 = 1 in. Far mark B: 30 + 1 = 31 in from the coupling end. Near mark A: 31 - 8 = 23 in. Check from the other direction: 23 in of straight pipe, then the 8 in slant covers about 6.93 in of wall, so the second bend lands at 23 + 6.93 = 29.93 in along the wall, just ahead of the water pipe at 30 in. The arithmetic closes.

The same offset at 45 degrees, if the slant were too long for the space: marks 4 x 1.41, about 5-5/8 in apart; shrink by the field figure 4 x 3/8 = 1-1/2 in, by the exact figure about 1-5/8 in. Using the exact figure, B at 30 + 1-5/8 = 31-5/8 in, A at 31-5/8 - 5-5/8 = 26 in. Check: 26 + 4.0 (a 45 degree slant of 5.66 in covers 4.0 in of wall) = 30.0 in, on the obstruction's edge. Using the 3/8 in field figure instead, A falls at 31-1/2 - 5-5/8 = 25-7/8 in and the bend finishes at 29-7/8 in, 1/8 in early, which is harmless here. Where the light figure bites is the far end of the stick: the real shrink is about 1/8 in more than planned, so a run cut to the field figure stops short of a fixed box by that much.

What would change the marks. If the offset sits near the coupling end and the far end of the stick is cut to fit later, shrink moves no mark at all: it only means the stick is cut 1 in longer (for the 30 degree offset above) than the straight-line measurement. A 3/4 in EMT stick uses a 3/4 in bender with its own take-up, commonly 6 in; read it off that bender, never reuse the 5 in.

Finish test

• Stub height within 1/8 in of target, floor to end, with the stub plumb on a torpedo level.
• Offset depth within 1/8 in, measured between the two parallel runs with the pipe lying on the floor.
• No dog-leg. Lay the offset on the floor: both straight sections must lie flat at once. If one end rocks up, the second bend was not made exactly 180 degrees from the first; put the bender back on the second bend and twist the pipe gently against it, or cut the bend off and start over on short offsets.
• No kink. The bend is round, not flattened. NEC 358.24 requires that the conduit not be damaged and its internal diameter not be effectively reduced, with a minimum radius set by Chapter 9, Table 2; the bender shoe produces it, a bend made over a knee or a step does not.
• Shrink accounted for: the run lands where the layout said it would, not 1 in short at the next box.

References

• NFPA 70, National Electrical Code, 2023 edition (2020 where the section moved), as adopted by your jurisdiction: 358.24, 358.26, 358.28, Chapter 9, Table 2
• The hand bender manufacturer's marking and instructions for take-up, gain and degree marks
• See related: How to Run EMT for a New Circuit in a Tenant Space; Conduit Fill + Sizing Quick Reference