Ground Screws

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petersonra said:
mcmaster carr even has green ones!

Green Chromate Zinc-Plated Finish
3/8" 92597A400 $6.82 per Pack of 25

1/2" 92597A500 6.99 per Pack of 25
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But those are not self drilling.
 
TOOL_5150 said:
But does anyone have any good ideas for tapping holes when the panelboard is allready installed, and you dont have much more than 1/4" - 1/2" of clearance behind the panel?
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You can get bottoming taps that don't have the extended point, and are only slightly harder to start.

bottoming.jpg

electricman2 said:
Simply drilling a regular panel enclosure using a 10-32 tap will not provide enough threads to secure a ground or anything else.
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You must be using thin metal. I have added aux. ground buses by drilling and tapping, and have not stripped a hole yet.
 
I remember reading that you were required to have a specific amount of treads and I thought the number was 3..I also do not know of a self tapping ground screw..I like the Greenlee drill taps and own 2 sets..Now during this thread I do have a question concerning ground screws..I have been doing this for awhile now and have never failed an inspection..When I need to add a ground in a box I use these Marson Steel Klik Thread-Sert..What do you think of these for adding ground screws in a box??

www.ros-master.com/pdf/2067-3818/2837.pdf
 
Pierre C Belarge said:
I am stretching here...from somewhere in my memory...maybe someone else here can help.

Tapping a panel enclosure for the grounding screw is not permitted, one would need a bolt and nut or other effective means.

When a manufacturer taps a box, they actually put a "dimple" in the box creating a little more "meat" at the location so there is enough threading for the screw to catch. When we drill and tap there will not be enough threads.
Of course if I am wrong, it will be established before the end of the day.
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I have seen many panels and boxes with the dimple as you describe, but as many boxes and panels with hole predrilled and not pierced for grounding.

I feel that it is OK to drill and tap a ground screw if the enclosure is not too thin. The thickness of a standard 4" sq, 6x6 or panelboard is thick enough.
 
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ItsHot said:
Use tech screws, and keep a lot of those little bottles of model paint handy, preferably green!!
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I think you meant Tek screws. But aren't those really sheet metal screws which are prohibited for grounding?


fastenmsc_1974_23772991


fastenmsc_1974_23786510
 
infinity said:
I think you meant Tek screws. But aren't those really sheet metal screws which are prohibited for grounding?
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IMO that would depend on the threads.

If it has standard machine threads IMO it is not a sheet metal screw.
 
i say yes

i say yes

Pierre C Belarge said:
Is there such an animal as self threading machine screws?
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the 10-32's i use at work are self threading. they have a triangular tip for the first few threads and then are round from there.
 
Pierre C Belarge said:
Is there such an animal as self threading machine screws?
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Definitely... the issue has been finding self-drilling and self-threading in a single machine screw.

AFAIR, it was determined a few weeks ago that nobody had the magic bullet for this....

hehe... just searched for the thread and realized this is the one! Why the heck is this thread still alive? I liked Minuteman's suggestion.
 
I know that there are screw manufacturers around that will make any kind of screw you want, but I'm guessing that making a self drilling self tapping machine screw for the specific purpose of bonding electrical grounds is just a liability issue that isn't worth taking on.
 
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