Bender types

Every bender does the same job: it holds the conduit against a curved shoe and forces it round. They differ in how much force they have, which sizes they take, and what the mark lines up with. The calculator needs to know which one you are using, because the shoe’s radius and deduct set every mark. Pick the bender, then the size and conduit.

Hand benders

A cast aluminum or iron head on a handle, for EMT up to 1 1/4" and the smaller rigid and IMC sizes. You hold it down with your foot and pull the handle. The head has an arrow, which the deduct is measured to, and usually a second mark (a star, teardrop or notch) for the center of a bend. Bender Specs records the angle that mark is for as Center notch is for, normally 45°.

Mechanical (Chicago) benders

A floor-standing frame with a large shoe turned by a long lever. They take rigid and IMC up to about 1 1/2", and some take EMT up to 2". The deduct is measured to a benchmark on the shoe, which the marks list calls the arrow, and marks line up with it just as on a hand bender.

Electric benders

A motor turns the shoe, so 1/2" to 2" EMT, rigid and IMC bend without the effort. Some have a separate shoe for each size (a set of 180° shoes, which can bend past 90°), some a single shoe, and some a combo shoe with grooves for several sizes and types. The benchmark works like a hand bender’s arrow. Where a shoe has a limit on how far it bends in one go (Most in one shot in Bender Specs), asking for more turns the result orange.

Hydraulic benders

A hydraulic ram does the work, for 2 1/2" to 4" conduit and heavy rigid. There are two kinds, and they mark differently.

• Table and cam-track benders turn the shoe like a big mechanical bender. The deduct is measured to a benchmark ahead of the bend, and marks work as on any other bender.
• Push-type benders (one-shot, rigid only) lay the conduit across two supports while a ram pushes the shoe into it between them. Their deduct is measured to the middle of the shoe, and the bend forms evenly on both sides of it. For these the calculator puts every mark on its bend’s center, whatever Place marks on says, and you line each mark up with the middle of the shoe (the benchmark the marks list calls the arrow). The hook direction and Flip make no difference, and Bender Specs shows no shoe center marks.

Shoes and conduit

• A shoe (the head, on a hand bender) has a groove for one trade size of one conduit type, and its radius, deduct and gain belong to that pair. Some grooves take two, such as 3/4" EMT and 1/2" rigid, with the same numbers.
• EMT is thin-wall tubing; IMC and RMC (rigid) are heavier, threadable pipe. At the same trade size their ODs differ, so pick the right type even when the shoe is the same.
• PVC-coated rigid is fatter than bare rigid and needs its own shoes, so it has its own entries. PVC conduit is bent with heat, not a shoe, and isn’t covered.
• Multiplier method is no bender at all: textbook math with sharp corners, for when you don’t know the shoe or want to check against a chart.
• If yours isn’t listed, use Add your own bender and enter the deduct and the gain printed on it, or the radius if you know it.