The use of "Drywall Screws"

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jfairfax

Member
Location
Indianapolis
Occupation
Director of Operations - Electrical Division
Would like some input on the use of "Drywall Screws" being used for light fixture yokes. I say no. Can't find in the code where it says you can't. 406.5 refers to receptacles. 404.10 refers to switches.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Would like some input on the use of "Drywall Screws" being used for light fixture yokes. I say no. Can't find in the code where it says you can't. 406.5 refers to receptacles. 404.10 refers to switches.
a drywall screw is not a machine thread. my guess would be the instructions tell one to use a machine thread, such as 6-32.
 

jfairfax

Member
Location
Indianapolis
Occupation
Director of Operations - Electrical Division
a drywall screw is not a machine thread. my guess would be the instructions tell one to use a machine thread, such as 6-32.
Thanks Bob. I understand the machine screw and have argued this more than once. Besides being an unworkmanlike installation, I have always said that the "drywall screw" is not listed or rated for that type of installation. Just always have those who want to continue to argue about it. There is a note in the handbook Article 404.10 that mentions the use of machine screws or listed assemblies and recommended by manufacturer's instructions to preclude the use of drywall screws.
Thanks again!
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Depending on where the box is installed would 300.6 play a part?
I’ve been really aggravated at Sheetrock screws that have rusted out and the head breaks off.
If I were to use something like that I would prefer decking screws. The neck is bigger, the metal is softer and less brittle so the heads won’t pop off, and decking screws won’t rust out.
 

jfairfax

Member
Location
Indianapolis
Occupation
Director of Operations - Electrical Division
Commercially, I have never seen any type of screw used for electrical installations except the correct machine screws. Maybe sometimes an oversized 8/32 because someone got crazy with their drill while installing the device. Residentially is where this seems to run rampant. What I don't understand is 99.9% of the time the provided machine screws that are shipped with the fixture. Get thrown on the floor or in the trash. That is something I will never understand. The problem I see with using any other type of screw is that it does not make good contact with the box. I have seen devices literally come out of the box when a drywall screw was used, just from use.
 

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Drywall screws are a hard brittle steel, and the head can break off, so they are not recommended for heavy loads, IE cabinets.
There shouldn't be a need but perhaps a code change is in order.
Unfortunately, the AHJ won't see the incorrect screw unless they take the luminaire apart
 

jfairfax

Member
Location
Indianapolis
Occupation
Director of Operations - Electrical Division
What is a "light fixture yoke"?
The adjustable strap that mounts to the box and then the fixture mounts to the strap. Sometimes adjustable. Sometimes just a flat piece that has a center threaded hole for the threaded nipple that the canopy attaches to. Have just always called them that. If there is another term, please enlighten me.
 
The adjustable strap that mounts to the box and then the fixture mounts to the strap. Sometimes adjustable. Sometimes just a flat piece that has a center threaded hole for the threaded nipple that the canopy attaches to. Have just always called them that. If there is another term, please enlighten me.
Oh ok, I call them "fixture bars".

Seems pretty hack to me to use a drywall screw rather than an 8-32. Tough to find a specific code violation though other than "manufacturers instructions 110.3.

I am definitely in the "drywall screws are for drywall" crowd
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Bugging someone about a screw is the best way to earn a micro manager label, I try to have the correct materials available so people wont be tempted to improvise or borrow from other trades.
Allot of times the screws that come with fixtures are not optimal, are metric, or strip out.
What I did was took an small area of our shop and filled it with grab and go boxes of #1-2 square 6-32, 8-32, 10-32, 1/4-20 and so on screws of all sorts of lengths and head types flat head button head etc.
Then each van has a orginizer for each size. I also provide tap-n-thread bits so if say a #6 strips out they can tap it to a #8 etc.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Oh ok, I call them "fixture bars".

Seems pretty hack to me to use a drywall screw rather than an 8-32. Tough to find a specific code violation though other than "manufacturers instructions 110.3.

I am definitely in the "drywall screws are for drywall" crowd
Drywall screws are very popular in community theater in my area since they are cheap. Since sets only go up for 6 weeks or so, longevity isn't an issue.
 
Drywall screws are very popular in community theater in my area since they are cheap. Since sets only go up for 6 weeks or so, longevity isn't an issue.
I don buy that argument. So a 5 pound box of 3" drywall screws is $25. The good star drive deck screws are far superior:. No annoying Phillips drive, they don't break, they have a drilling tip that makes them drive much easier. They are $35 per 5 pound box. Save $10 for $100 worth of annoyance and frustration and extra time, to each their own.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I don buy that argument. So a 5 pound box of 3" drywall screws is $25. The good star drive deck screws are far superior:. No annoying Phillips drive, they don't break, they have a drilling tip that makes them drive much easier. They are $35 per 5 pound box. Save $10 for $100 worth of annoyance and frustration and extra time, to each their own.
We're typically using 1-1/4" to make up flats and secure them to the stage and very occasionally we use 2". It's all 1x2 and 1x3 pine with the frame covering of your choice. Plus, deck screws don't come any shorter than 2-1/2", way too long for most set construction purposes other than making risers.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Drywall has become a slang term for many screws.

The actual drywall screws are very brittle and have a fairly large bugle head. Their heads often split thin wood.

There are many other construction screws beside the ones for decks. I use have several types in sizes less than 2"
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Allot of our electrical stuff already comes with #2 square, and we also use square drive button head wood and tech screws for conduit straps etc.
So I source #2 robertson square for the deck / drywall screws on my grab-n-go shelf at the shop.
I get boxes of I think 2500 or so in a few sizes 1-1/4 - 3 -1/2
 
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