1/2" rigid (RMC) bender deduct and take-up
By Andrew ·
Quick answer
Hand benders bend 1/2" rigid in the 3/4" EMT head and deduct 6", the most common figure among the 27 shoes in BendMate. Electric benders run higher: 7 1/2" on a Greenlee 555, and push-type hydraulics measure to the shoe center, so theirs is only 1 5/16". Mark the conduit at the stub length minus your deduct: a 12" stub with a 6" deduct is marked at 6".
1/2" rigid (RMC) deduct by bender
27 shoes in BendMate bend 1/2" rigid (RMC). The most common deduct is 6".
| Bender | Deduct (take-up) | Centerline radius |
|---|---|---|
| Gardner Bender B300 series one-shot (Rigid-only hydraulic table bender) | 1 1/8" | 3 5/16" |
| Greenlee 884 / 885 (Hydraulic, rigid only) | 1 5/16" | 4" |
| Gardner Bender Sidewinder (Mechanical, Chicago-style) | 5 1/4" | 3 1/4" |
| Current Tools 750 / 751 (Chicago bender, rigid and IMC) | 5 1/2" | 2 5/8" |
| Greenlee 1800 / 1801 (Mechanical, rigid and IMC) | 5 1/2" | 2 5/8" |
| Gardner Bender Big Ben (Aluminum hand bender) | 6" | 5 3/16" |
| Greenlee 1818 (Mechanical) | 6" | 2 11/16" |
| Greenlee aluminum hand bender | 6" | 5 1/8" |
| Greenlee iron hand bender | 6" | 5 1/8" |
| IDEAL aluminum hand bender | 6" | 4 1/2" |
| IDEAL ductile iron hand bender | 6" | 4 1/2" |
| Klein Tools aluminum hand bender | 6" | 5 1/2" |
| Klein Tools iron hand bender | 6" | 5 1/2" |
| Milwaukee aluminum hand bender | 6" | 4 1/2" |
| Milwaukee iron hand bender | 6" | 4 1/2" |
| Southwire aluminum hand bender | 6" | 4 1/2" |
| Current Tools 747 Omni (Combo shoe) | 7 1/2" | 4 1/4" |
| Current Tools 77 Series (Single shoe) | 7 1/2" | 4 1/4" |
| Greenlee 555 (Combo shoe) | 7 1/2" | 4 1/4" |
| Greenlee 555 (Multi-shoe, PVC-coated rigid) | 7 1/2" | 4 1/4" |
| Greenlee 555 (Multi-shoe) | 7 1/2" | 4 1/4" |
| Greenlee 555 (Single shoe, PVC-coated rigid) | 7 1/2" | 4 1/4" |
| Greenlee 555 (Single shoe) | 7 1/2" | 4 1/4" |
| Gardner Bender B2000 Cyclone (Large combo shoe) | 7 3/4" | 4 3/8" |
| Greenlee 854DX (Large combo shoe) | 8" | 4 1/4" |
| Current Tools 77 Series (Multi-shoe) | 8 1/2" | 4 3/8" |
| Gardner Bender Electric Sidewinder (Multiple 180° shoes) | 8 1/2" | 4 3/8" |
Why 1/2" rigid rides in the 3/4" EMT head
Rigid has a thicker wall than EMT of the same trade size, so it is wider: 1/2" rigid is 0.840" across, against 0.706" for 1/2" EMT and 0.922" for 3/4" EMT. The hand benders in BendMate have no separate rigid head. The 3/4" EMT head carries 1/2" rigid in the same groove, so it bends it on the same radius and takes the same deduct, 6".
Every hand bender in the table agrees on 6". That is the number cast near the arrow of the 3/4" head, not the 5" printed for 1/2" EMT.
mark at = stub length − deductFour kinds of bender, four kinds of number
- Hand benders: 6", with the mark on the arrow.
- Mechanical (Chicago-style): the Greenlee 1800 deducts 5 1/2", but its 1/2" rigid shoe bends on a 2 5/8" radius, under the NEC minimum of 4". Greenlee and Current Tools both say to bend 1/2" rigid in the 3/4" position to meet code, and give no deduct for doing so.
- Electric: the Greenlee 555 single-shoe group deducts 7 1/2". Other electric shoes in the table go as high as 8 1/2".
- Push-type hydraulic: the Greenlee 884/885 deducts 1 5/16" and the Gardner Bender B300 1 1/8". These are not misprints: on a push-type bender the mark goes on the center of the shoe, so the deduct is measured from the middle of the bend, not from a hook ahead of it.
So the 1 1/8" to 8 1/2" spread in the table is mostly about where each bender wants the mark, not the conduit. Use the number that belongs to your bender’s shoe and its own benchmark.
Marks for common 1/2" rigid stubs
| Stub length | Hand bender (6") | Greenlee 555 (7 1/2") | Greenlee 884 (1 5/16") |
|---|---|---|---|
| 10" | 4" | 2 1/2" | 8 11/16" |
| 12" | 6" | 4 1/2" | 10 11/16" |
| 15" | 9" | 7 1/2" | 13 11/16" |
| 18" | 12" | 10 1/2" | 16 11/16" |
| 24" | 18" | 16 1/2" | 22 11/16" |
- Stub length
- 12"
- Deduct
- 6"
- Mark at, from the end
- 6"
Machines also need some conduit past the hook or the shoe to hold on to. Each manual gives a minimum distance from the end, so check it before you bend a short stub.
IMC and PVC-coated rigid
Most benders bend IMC in the rigid shoe, and the most common IMC deduct for 1/2" is 6", the same as rigid. A few manuals print a separate IMC figure; where they do, BendMate uses it.
The rows marked PVC-coated rigid are Greenlee 555 shoe groups made for coated conduit. Greenlee gives them the same deducts as the plain rigid groups.
Confirm it with a test bend
- Find the deduct for your shoe: cast on a hand bender’s head, printed in a machine’s manual or on its chart.
- Bend a test 90 in a scrap of 1/2" rigid, marked for a 12" stub.
- Measure from the end to the back of the bend. Rigid springs back more than EMT, so check the bend is a full 90° before you measure.
- Correct the deduct by any difference from 12" and keep the number with the bender.
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.
Free for offsets, saddles, 90s and kicks with a hand bender. No signup.
Common questions
What is the deduct for 1/2 inch rigid conduit?
6" on a hand bender, the 3/4" EMT head’s number. Machines differ: 7 1/2" on a Greenlee 555, 5 1/2" on a Greenlee 1800 and 1 5/16" on a push-type Greenlee 884.
Is the deduct for 1/2 rigid the same as 1/2 EMT?
No. On a hand bender 1/2" rigid rides in the 3/4" EMT head and takes its 6" deduct, not the 5" of 1/2" EMT.
Can I bend 1/2 inch rigid with a hand bender?
Yes, in the 3/4" EMT head. Rigid takes more effort than EMT and springs back more, so check the angle after each bend.
Why is the deduct on a hydraulic bender so small?
On a push-type hydraulic such as the Greenlee 884 the mark goes on the center of the shoe, so the deduct, 1 5/16" here, is measured from the middle of the bend instead of from a hook ahead of it.