"Josh" wrote in message
...
I'm adding a couple of steel outlet boxes and switch boxes in my
residence, fed by 12-2 w/g Romex. I've noticed in Lowes some of the
boxes have clamps built inside to secure the Romex, and some don't.
Are clamps required by NEC?

The other thing I'm wondering about is the knockout holes on the sides
and back of the boxes. Are rubber grommets required for the holes I
run the Romex through?


Depending upon the box type and composition, clamps or connectors may or may
not be required. For metal boxes, I'm a big fan of the Arlington button.
They take up very little space and are easy to use. Be sure to use boxes of
adequate size for the size and amount of cables you plan to use in each box.