Two holes on each side of 4" square box

[Conduit Phil]

Two holes on each side of 4" square box -- what are they for?

 

[TOOL_5150]

I noticed that those 2 holes are where the brackets are spot welded on. Im also interested in a definite answer.

~Matt

 

[buldogg]

Screw holes for mounting

 

[Conduit Phil]

I'm looking around at various catalogs, I wonder if they are for these:

RACO 961

or

Steel City 52171-OW

 

[mcclary's electrical]

I use those holes sometimes to screw directly to a stud. But i think they will line up with the brackets you have shown.

 

[infinity]

Seems like Conduit Phil nailed the answer.

 

[Buck Parrish]

I use those holes sometimes to screw directly to a stud.

Me too: .....................

 

[ivsenroute]

You can mount directly to a stud with those holes but will then need an extension ring.

 

[Buck Parrish]

You can mount directly to a stud with those holes but will then need an extension ring.

I just use a plaster ring

 

[ivsenroute]

I just use a plaster ring

That is what I meant. Plaster ring, mud ring, etc.

 

[mcclary's electrical]

You can mount directly to a stud with those holes but will then need an extension ring.

You will need the plaster ring anyway.

 

[K2X]

They are for holding your meter probe to ground or holding both probes while your messing around in the box.. :grin:

 

[cowboyjwc]

You will need the plaster ring anyway.

Why? You could use a raised cover.

 

[peter]

Originally those little holes were so the manufacturer could screw on some sort of brackets. Nowadays the brackets are spot welded on but there is some sort of inertia going on.
I would like to point out that some of these holes, in the 4 square boxes are the right size to simply tap for a 10-32 grounding screw. If you have the proper grounding screw, such as the Dottie 10-32 ST, these will self tap in one of those little holes.
~Peter

 

[220/221]

For 35 years I have assumed they are mounting holes. It never occurred to me to ask.

 

[c2500]

They are good for tapping and using the ground screw in them when you have back to back boxes.

c2500

 

[Jim W in Tampa]

Dang, i thought they were for electrons to fall out if we overload the box.

 

[nakulak]

In the rare event that you want to use the box as old work, you need the brackets to hold it from falling in the wall, hence the screw holes.

 

[TOOL_5150]

I have never seen those holes come threaded though.

~Matt

 

[celtic]

They are good for tapping and using the ground screw in them when you have back to back boxes.

c2500

I have never seen those holes come threaded though.

~Matt

Tap them.

Before dimpled EGC screw holes...they were flat - much like the world was.
Shooting a 1900 to a steel beam left no place for a screwed in EGC ~ sure you could use a clip, but the world was flat then and clips didn't exist.

It's true.

:grin: