They’re very similar in most regards, but there is one big difference between the two cables. In the electrical world, AC or BX cables do not come with a ground wire while MC cables do. … Both are essentially just names for armored cable.

Is BX cable legal?

BX is accepted by the National Electrical Code (NEC). Older BX cables without an internal bonding strip are not accepted by NEC.

What is the difference between MC and Greenfield?

Flexible metal conduit (FMC) is commonly called “Greenfield.” The main difference between MC cable and FMC is that FMC doesn’t have the insulated wires pre-installed; you have to pull them through instead. … It also allows you to add wires in the future, something you can’t do with MC cable.