Attaching grounding pigtails

[renosteinke]

Your typical metal outlet box tyipically has a hole in the back that is just the right size to accept one of those green screws. Sometimes, it;s even marked "ground.
The trouble is, when you have to mount one on a concrete wall, the green screw will not penetrate into the concrete. Sure, Appleton makes theirs with a "blister" to accept the green screw, but what are you to do about an already installed box- or if your supply house only carries another brand?

I have discovered that the green screws will tap into those little holes in the sides of the box, and will do so without interfering with any cover you might mount on the box. (I've always wondered what those little holes were for.)
Does anyone have a problem with using these side holes to mount the green screw?

 

[sparky46514]

Re: Attaching grounding pigtails

If I am mounting a flat backed box on any flat surface I drill a relief hole so that the ground screw can be mounted in the ground screw hole.

 

[peter]

Re: Attaching grounding pigtails

Renostrike,
I heartily agree with you. Those holes are just the right size for tapping 10-32 screws, at least on the 4" sq. boxes.
Dottie makes two types of ground screws and #1032TC will cut its own threads in those holes with your screw gun. The other, more common, one has a "dog point" which is square in cross section or a small cyliner *** the tip. For these, you must use a tap. I am not aware of any price difference per box.
(I have no affiliation with L.H. Dottie.)
~Peter

 

[Guest]

Re: Attaching grounding pigtails

You might also consider using a grounding clip: