FTM 180: Can you interchange drywall screws and wood screws?

This edition of the Fastener Training Minute with Carmen Vertullo was originally published September 22nd, 2022 as “Can we interchange drywall screws and wood screws.” during episode 180 of Fully Threaded Radio.

Hi Everyone, this is Carmen Vertullo with the Fastener Training Minute coming to you from the Fastener Training Institute and the AIM Testing Laboratory here in the beautiful. El, Cajon California.
It’s a day where we are seeing horrible weather, trees are blowing down outside my window as I talk. So, this will remind me when I listen to this.

Anyway, today, we are not talking about talking about trees, we’re talking about some very generic screws and how they are often interchanged with each other. Sometimes correctly or I guess I would say OK, and sometimes not. Those two screws are what we would commonly call drywall screws or gypsum board screws. Bugle head #6, #8 by 1 5/8 type drywall screw. and wood screws.

Wood screws are very different animal from drywall screws, and often times, people will use drywall screws in the place of a wood screws. When I come back, I’ll tell you how you can do that effectively and how sometimes you shouldn’t do it.

Well, welcome back, everybody. It’s the Fastener Training Minute today we’re talking about drywall screws vs. wood screws.

Drywall screws and wood screws have some similarities. And here are the ones I can think of off the top of my head. They both function as a flat head screw. Notice that I said function: technically a drywall screw has a bugle head, not a flat head, but it functions as a flat head. They have tapping screw threads or spaced threads. They both have a sharp points. If the drywall screw happens to be yellow, zinc, plated, they have a similar color and they have a Phillips Drive in many cases. So you would expect that with all these similarities, you could have some cross usage between the two of them.

However, they also have many differences and here are some of their differences: the material of a brass wood screw, for example is brass. So there are steel wood screws and they are not heat treated or hardened. Whereas the drywall screw is made out of steel and it, is heat treated. But believe it or not, the brass would screw probably is stronger than the heat treated drywall screw because of its corrosion resistance. A brass wood screw is far superior to a drywall screw for corrosion resistance and the zinc-plated steel would be about the same. The point of a drywall screw is much sharper than that of the wood screw and it can pierce wood and maybe even some very thin metals easily. A wood screw has a coarse thread and the drywall screw in some cases can have a fine thread, but most drywall screws have a sharper deeper and coarser thread than a wood screw. So it’s easier to put them into material without having any kind of a pilot hole. Regarding thread length, drywall screws are typically threaded to the head, or pretty close, but long versions of wood screws are not threaded to the head. The head of a wood screw is actually an 82-degree flat head and of course, a drywall screw has a bugle head.

So where do we see these screws interchanged?
Well, if you’re building wood furniture making stuff out of particle board or even wood., and you’re not a really picky craftsman, a drywall screw works great, in many cases, you can put it into the wood without having to drill a pilot hole, it’ll sink in often times without leaving much of a bulge. So just for some cheap wood assembly. It’s okay. If you’re doing the job right you should use a common wood screw with a 82° head. These screws have a tapered body and they require a pilot hole: the really good Craftsmen would use a drill that would make a tapered pilot hole and also a through hole for the top piece and a countersink, all in one operation. So it’s a very cool tool. You can only get those in woodworking stores. You probably would not find it at the Home Depot. The wood screw is commonly used to attach door hinges and I’m talking about like your office door. If you go look at your office door, nope. You’ll notice the hinge requires a flat head screw. Sometimes we’ll see some people use drywall screws in place of that application but that is a No-No for two reasons: they’re not strong enough and they are very likely to break. If you over-tighten the screw and it breaks, you cannot remove it. There’s no repair for that broken drywall screw that’s underneath the door hinge.

Well, as usual, this Fastener Training Minute came to me from a client who was having some confusion about where they could use wood screws vs. drywall screws. You would never interchange a drywall screw with a wood screw: wood screws will not work for installing drywall, so would be silly to do that. So keep that in mind. Bugle head drywall screws are very good for other types of applications that are not drywall, that would typically maybe a wood screw would work. These are things like holding lightweight devices on to walls and ceilings like smoke detectors, thermostats and CO2 detectors and other types of small sensors and cameras.

Electricians love to use these drywall screws to attach their electrical boxes to studs in the build-out. And that’s because they’re very easy to use and you can put them in off-angle like you often have to do with the installation of electrical boxes and conduit and conduit clips. And most importantly, they are really cheap, probably the cheapest screw that we have is our #6 #8, by maybe 1 5/8 drywall screw.

So that’s what you need to know regarding using and misusing drywall screws and wood screws and how they have some cross application. This has been Carmen Vertullo with the fFastener Training Minute, thank you for listening.