plastic vs. metal junction boxes

[john_williams1000]

In an unused area (such as an attic with no stairway access, not used for storage) I need to make some electrical connections. (Don't worry, my building inspector is involved!) I will be connecting NM to NM cable.

So I need to decide the best junction boxes to use, plastic vs. metal. Obviously, I want to do the best job possible, and the small price difference between plastic and metal is not a factor.

Thanks for your thoughts...

[BobK207]

I'm old school, I like metal. They're stronger.

But then I use emt or flex & pull 12 gage stranded THWN/THHN wire.

The nice thing about the plastic boxes is that you can just poke the Romex in & the boxes have built in clamps.

cheers Bob

[xrongor]

for junction boxes i like nice, deep, roomy metal boxes.

randy

[scott_z500]

I also only use metal boxes. Besides being stronger, it's unlikely that you'll strip the threads in any of the screw threads. In plastic boxes I'd worry about that.

[The Real Tom]

Couple reasons why nonmetalic come to mind as a choice.

1. You don't have to ground them.
2. Harder to cut your fingers on.
3. Lighter
4. Fewer open seams for dust, dirt, sparks to fall into and out.

Just playing devil's advocate since the current reply vote is metal. :-P

later,

tom @

[Harry Everhart]

It reminds of the plastic or paper routing in the grocery store.

I like plastic junction boxes because they are - cheaper easier to install rust proof insulated non conductor less chance of cutting yourself no metal waste pieces easy to clean pretty :-)

[Jag Man]

My two cents worth:

As a DIY homeowner with 1" plaster on gyb-board lath walls, I have to point out that plastic offers far better options for old work. I really like the Carlon deep old work boxes. The push-in ports with the little trap doors that won't let it pull back out or pretty good, but can be difficult if you make a mistake and have to pull it back out.

Someone mentioned the possibility of stripping the threads. Never had that problem.

Ed

plastic

[Doug Boulter]

john [e-mail] wrote on 19 Mar 2005:

I actually like the hard plastic (bakelite?) boxes, but they're difficult to find these days. My second choice is metal.

However, one advantage of plastic that no one has yet mentioned is that for the same rough box size, the plastic box has more capacity. That can be a real help in some situations.