Where do I find the take-up for my bender?

Stamped or cast on the bender head, one figure for each pipe the head takes. If it has worn off or your stubs keep landing wrong, bend a test stub on a scrap: finished height minus the mark is your take-up.

Why is my 90 too tall?

If every stub is tall by the same amount, the take-up you are using is too small by that amount. Add it to your take-up and the next stub lands. If the error changes from stub to stub, it is technique: the pipe creeping in the shoe, or the arrow read from a different angle each time.

When do I use the star instead of the arrow?

When the back of the bend has to land on a measurement: the second 90 of a back-to-back, or a 90 whose back must sit against a wall measured from the other end of the pipe. Mark the pipe where the back should be and put the star on the mark.

What is the shortest stub I can bend?

It is set by the hook: the end has to reach past the mark far enough for the hook to hold it. If height minus take-up puts the mark too close to the end, bend it longer and cut it down, leaving 1" (25 mm) or so for a square cut.

How to bend a 90

To bend a 90° stub-up: take the take-up for your bender off the stub height, and mark that distance from the end of the pipe. Put the arrow on the mark with the hook toward that end, stand on the pedal, and pull until the stub stands plumb — a touch past, and let it relax back. A 16" (406 mm) stub on a bender stamped 6" (152 mm) gets its mark at 10" (254 mm). Check it with a level and a tape.

Take-up: read it off your bender

The mark goes at height − take-up from the end. The sweep gives the take-up back, so the finished stub stands to the full height, measured to the back of the bend.

A 90 sweeps round the shoe, and the sweep uses up length. The take-up is how much: put the arrow on a mark and the finished stub stands the take-up taller than the mark.

mark from the end = stub height − take-up

The take-up belongs to the bender: stamped on the head, one figure per pipe it takes, and different on another make. Read it off the tool — and if the stamp has worn off, or your stubs keep landing wrong, one test bend on the take-up page gives you the real figure and saves it for the stub-up calculator.

Bending a stub-up, step by step

Measure. Decide the stub height: from the end of the stub to the back of the bend. Read the take-up for this pipe off your bender, or use the figure from your own test bend.
Mark. Measure height minus take-up from the end that will stand up. Draw the line all the way round the pipe, and write the figure with an arrow pointing to that end.
Line up. Pipe flat on the floor, hook toward the end you measured from. Slide the bender until the arrow sits on the line, looking from the side.
Bend. Weight on the pedal, take up the slack, check the arrow is still on the line, then one steady pull until the stub stands plumb. Go a touch past and let it relax back.
Check. Level on the stub for plumb, then stand it on its end and tape from the floor to the back of the bend. If it is off, note by how much before you bend the next one.

Worked examples

The take-ups below are examples. Use the one on your bender.

A 16" (406 mm) stub

Say your bender is stamped 6" (152 mm) for this pipe. Mark 16 − 6 = 10" (254 mm) from the end, arrow on it, pull to plumb. Floor to the back of the bend reads 16" (406 mm).

A metric stub: 11 13/16" (300 mm)

Say your take-up is 4 15/16" (125 mm) — an example figure; use the one on your bender. Mark 300 − 125 = 6 7/8" (175 mm) from the end. Write 175 and an arrow on the pipe and bend.

It came out long

You marked 10" (254 mm) for a 16" (406 mm) stub and it stands 16 1/4" (413 mm). The real take-up for this bender and this pipe is 16 1/4 − 10 = 6 1/4" (159 mm), not the 6" (152 mm) you used. The next 16" (406 mm) stub gets its mark at 16 − 6 1/4 = 9 3/4" (248 mm).

Two 90s, backs 30" (762 mm) apart

First leg 12" (305 mm) with a 5" (127 mm) take-up: mark 7" (178 mm) from the end and bend. Hold a block against the back of that leg, tape 30" (762 mm) along the run from it, and mark. Hook facing the first bend, star on the mark, pull the same way.

Checking plumb

Long end flat on the floor, torpedo level on the side of the stub that faces along the run. Plumb: you have 90. Leaning back over the run: over-bent. Leaning away: under-bent. Then check the face at right angles — a lean that way means the long end was not flat when you pulled.

A few degrees under is easy: bender back on, arrow on the same line, and pull a touch more. A degree or two over eases back by hand; much more, and it is quicker to cut it off and start again.

When it comes out long or short

Measure every stub until they land, then read the error:

Off by the same amount every time — the take-up is wrong for this pipe or shoe. New take-up = finished height − mark.
Off by a different amount each time — technique: the pipe crept in the shoe (the stub stands tall), or the arrow was read from above, not the side.
Off by a round inch or 100 mm — a burned tape, the burn not taken off.
Short by roughly the pipe's thickness — measured to the inside of the bend, not the back.

Fix the figure, not the method: holding the arrow a little off the line to make up for a wrong take-up is right on this stub and wrong on every other bend.

The second 90: back-to-back and the star

A back-to-back is two 90s the same way, making a squared U. The first is an ordinary stub on the arrow. The second has to put its back on a measurement: the job of the star (the back-of-bend mark). Bend the first 90. Measure the distance between backs from the outside of the first leg along the run, and mark it. Turn the bender round so the hook faces the first bend, put the star on the mark, keep the first leg pointing straight up, and pull the same direction. Tape across the two backs to check.

A U wrong by the same amount every time had its second bend on the arrow. No star on your shoe? The mistakes page finds the gap from one scrap U.

Measuring from a wall

Sometimes the fixed point is at the other end: the pipe comes out of a floor box and turns up tight against a wall. The distance from the box end to the wall is where the back of the bend goes. Mark it from the box end, put the star on the mark with the box end under your foot and the long end toward the hook, and bend. The back lands on the wall; cut the stub to height after. Pipe end 40" (1016 mm) from the wall: mark at 40" (1016 mm), star on it — no take-up in the sum.

A stub that must lift the run over something is a kick 90; the cut length of a run round a 90 is on deduct and gain.

What goes wrong

Stub leans sideways

What you see: plumb along the run, out of plumb across it.

Why: the long end was not flat on the floor, or the handle was pulled off to one side.

Fix: hard flat floor, handle pulled in line with the pipe.

Kink in the heel

What you see: a crease on the inside of the bend.

Why: handle pulled without weight on the pedal, so the pipe lifted out of the groove.

Fix: foot first. A kinked 90 is scrap.

U is the wrong width

What you see: both 90s fine, the distance between backs wrong.

Why: arrow on the second mark instead of the star, or measured from the first mark instead of the back of the first leg.

Fix: star on the second mark, measured from the back.

Questions

How do you bend a 90 degree stub-up in EMT?: Subtract the take-up stamped on your bender from the stub height and mark that distance from the end of the pipe. Put the arrow on the mark with the hook toward that end, stand on the pedal, and pull until the stub is plumb, a touch past for springback. Check it with a level and a tape.
Where do I find the take-up for my bender?: Stamped or cast on the bender head, one figure for each pipe the head takes. If it has worn off or your stubs keep landing wrong, bend a test stub on a scrap: finished height minus the mark is your take-up.
Why is my 90 too tall?: If every stub is tall by the same amount, the take-up you are using is too small by that amount. Add it to your take-up and the next stub lands. If the error changes from stub to stub, it is technique: the pipe creeping in the shoe, or the arrow read from a different angle each time.
When do I use the star instead of the arrow?: When the back of the bend has to land on a measurement: the second 90 of a back-to-back, or a 90 whose back must sit against a wall measured from the other end of the pipe. Mark the pipe where the back should be and put the star on the mark.
What is the shortest stub I can bend?: It is set by the hook: the end has to reach past the mark far enough for the hook to hold it. If height minus take-up puts the mark too close to the end, bend it longer and cut it down, leaving 1" (25 mm) or so for a square cut.