What does the NEC require for bending conduit?

Two limits govern conduit bends: how many degrees of bend total between pull points, and how tight a radius each bend can be. For RMC, IMC, and EMT, sections like 344.26 and 358.26 cap the total of all bends between pull points, including offsets, at 360 degrees. Exceed that and the raceway is treated as having no accessible pull point in between, which becomes a conductor pulling and heat dissipation problem, not just a code violation.

Minimum bend radius

Bend radius is set by tables tied to trade size, generally found in 344.24 for rigid and IMC and the equivalent table for EMT, with tighter minimum radii for smaller trade sizes and looser radii required as trade size increases. A field bender marked with the correct radius takes the guesswork out, and factory elbows are manufactured to meet these minimums so they are always compliant when used correctly.

Why the 360 degree limit exists

Pulling conductors through a raceway generates friction, and every additional degree of bend adds resistance and can damage conductor insulation on a long pull. The 360 degree cap between pull points, along with the requirement for accessible pull or junction boxes at that limit, keeps pulling tension within what standard pulling lubricant and technique can handle without insulation damage.

Field takeaway

Count your bends as you go, including small offsets around obstructions, they add up fast on a run with several kicks. Stop at 360 degrees total and land a pull point, and always bend to the minimum radius for your trade size rather than eyeballing it.