Intermediate metal conduit (IMC) has a thinner wall than RMC and weighs about one-third less. IMC has a thinner wall than RMC and weighs about one-third less than RMC. The outside has a zinc-based coating, and the inside has an approved organic corrosion-resistant coating.

Does IMC rust?

The interior of Allied IMC is coated with a highly corrosion-resistant lubricating finish for easier wire-pulling.

Will metal conduit rust?

Typical EMT Type conduit will resist rust for a few years. It is however inevitable that it will rust. The most likely place for rust to start will be at the ends where it has been cut or along the surface where the finish has been scratched.