Drywall screws in steel work surprisingly well

[@EvanDunville]

The most Matthias part of this video is reusing a damaged screw because it was still mostly good.

[@alexmosqueira]

😂😂😂

[@minovskyecm3596]

'twas only a flesh wound on that screw.

[@RubixB0y]

That may be true, but let's not diminish the fact that this _entire_ video is very Matthias 😊

[@peterbarlow8912]

What about using the cutout from test holder for a test till destruction.

[@douglascrowder]

Waste not... want not.

[@ProfessionalNoun]

I have heard rumblings down at the lodge that you are a secret agent for the drywall screw industry.

[@MrErViLi]

Been using drywall screws for all kinds of applications, including steel. The issue, as you well know, is that they are hardened and can be brittle. They also have little to no shear strength. I've attached metal shelving to a metal stud with dry wall screws and when the shelf got overloaded, the screws just snapped instead of slowly bending like sheet metal screws would have. So drywall screws can definitely be used for more than drywall but the do have their limitations.

[@Octopusbeak]

huge variation in steel quality and hardness among them.

[@zachary3777]

Drywall screws have massive shear strength. The fact you can snap them means they are brittle, not weak. If you think they don't have shear strength try cutting one with a pair of tin snips.

[@MrErViLi]

@zachary3777 That's the point I'm making. They are brittle. They snap all of a sudden. I realize they're hardened.

[@ganjalfcreamcorn8438]

@@zachary3777 they have a weak working load. doesnt take much to snap them if applying a bending force. they have bad tensile strength. they are hardened, but thats what makes them bad for building.

[@BuriedAliveBySquirrels]

There's a book on my shelf titled "Everything I Know About Screws," which is humorously filled with only blank pages. But as a mechanical engineer, and one who watches your channel regularly, sometimes I'm tempted to ruin the joke by actually filling it out with all that I've learned.

[@BloodyMobile]

Start at the back. That way you put the empty pages to good use without ruining the joke. At least not until you filled it.

[@Ammoniummetavanadate]

This is what happens when you let wood guys near the metal. Definitely good to know that in a pinch I can use these instead of self-tapers, good video!

[@LykeArgy]

yeah i learnt that installing magnetic contacts (for security) on old school 4mm metal doors lmao

[@profile5]

I have been happily using my giant box of drywall screws for various projects after watching your channel. THEY just want us to buy more different types of screws, I’m onto you Big Screw!

[@CitizenAyellowblue]

I'll say the obvious- they're screwing us...

[@cj09beira]

they trying to Screw us.

[@BloodSprite-tan]

I really like the self drilling heads on the drywall screws they make me happy personally.

[@dfresh1524]

It's all marketing. The more you can specialize each screw the more types you can sell $$$

[@jameshisself7375]

@@dfresh1524 When we see drywall screws in an airplane you might have a point. Until then NOPE.

[@P_RO_]

My experience with drywall screws shows them to be hard and from brittle to very brittle under bending, torsion, and shear loads because of their hardness. They can be very good for some purposes, but for going into metal like is shown here I prefer the "Tapcon" screws intended for concrete. Their hardness is lower and better regulated, and while the threads can 'smear' a bit going in metal, they hold very well and are much better under the mentioned loads and stresses. In thinner metals they can even hold against pullout better than tapping a thread for machine screws or bolts.

[@victorhopper6774]

way too expensive

[@jameshisself9324]

@@victorhopper6774 make more money

[@boots7859]

@@victorhopper6774 Tapcons seems OTT when you can get Grade 6/8 black nuts and bolts at Tractor Supply for $/# cheaper than HD/Lowes. I can't claim to have never abused some drywall screws, however if its going to hurt or be expensive to replace something that comes down, I spring the $2 for actual bolts.

[@vikassm]

+1 for the concrete screws! Of late I've started using 'Confirmat' or confirmative screws, ever since they've become available locally. Self tapping, coarse but very deep threads, and allen head too! I was dreading the price tag, but they're priced at ~US$12 for a box of 1000 screws 😯Time to load up 🤣

[@Volte6]

Matthias has been the champion of drywall screws for years. Not gonna lie, over the years I've been swayed to use them for all sortsa stuff.

[@stevebabiak6997]

It should be noted that the drywall screws used here were the “fine thread” type rather than the “coarse thread” type.

[@matthiaswandel]

Very observant. I suppose you noticed noticed the coarse threaded ones right next to it in the opening shot for comparison?

[@stevebabiak6997]

@@matthiaswandel - I missed the opening bits, was distracted by the wife …

[@Vykori]

@@matthiaswandel you're so sassy lmao

[@MrTehkaiser]

​@@matthiaswandel it's good to see Matthias also doesn't suffer fools.

@@matthiaswandel yes you showed them but you could also clearly mention that they are fine thread while you are doing this much detailed video.

[@first_namelast_name4923]

You should follow up with a set of metric screws, imperial thread screws and those self-tapping screws for metal that have a tiny drill built-in at the tip of the screw. That would be a good comparison with drywall screws. There are also similar screws to those "drywall" screws but they are supposed to be used on wood. I do not know whether those are treated differently than screws that are specifically for drywall construction. By the way, here in Europe drywall is usually installed on a thin-walled galvanized "C" profiles and not wood as in North America.

[@leesass3602]

Drywall screws are very hard, but there are no control parameters during heat treating so they come with no guarantee of performance like grade 8 bolts do.

[@Laundry_Hamper]

Probably worth a bulk test of screws from many different manufacturers and batches. Mattias probably has drywall screws manufactured across several decades in yoghurt pots somewhere :P

[@arnearne12345]

VERY TRUE !! but you can with confidence say that they hold better then a grade 4 which is the requirement for general use :D

[@jameshisself7375]

@@arnearne12345 No you can't. The reason is even a grade 4 bolt **properly sized for the load** will outperform drywall screws by a mile. This testing is hugely flawed since he does no shear load testing and he extrapolates the loading to make his point. You can't upsize a drywall screw so it's load will only ever be what you see here and this is only tensile loading. A properly sized, installed and torqued bolt of any grade will blow this test out of the water.

[@karlkoehler341]

@@jameshisself7375 Sure, but the conclusion here is still valid. Namely, a drywall screw will hold plenty well in metal. On the other side, sheet metal screws also hold quite well in wood. And of course a drywall screw isn't the answer where traditionally you use a bolt with a nut ...

[@jameshisself7375]

@@karlkoehler341 No, that is not how fasteners work in any way. His test is valid only for the very limited scope he covered. Hugely flawed. I agree that drywall screws will hold 'plenty well in metal'. Now convert that to actual loads in shear, tensile, compression, vibration and other loads. Your fasteners do more for you than you realize and this testing is a massive disservice to you and the general public. For instance- look at the thread pitch. And no nut as you mentioned. Now do these same tests he did while subjected to any vibration at all. What do you think will happen? Do not be fooled by this foolish test. For wood in your house probably no problem and better than nails. But rust and a whole host of other things you are not thinking about make drywall screws no bueno for metal.

[@sbroz1424]

I would love to see you do that same test with self drilling and tapping screws

[@ronyerke9250]

I wonder if you can test for shear force across the screws, like something hanging from them (or pushing across their length instead of parallel to it).

[@MrQuickLine]

That tracks. The walls of those steel tubes look pretty dry to me.

[@matthiaswandel]

"drywall" came from the gypsum panels that you could screw on, mud the joints, and paint. As opposed to previous lath and plaster walls, whose construction process was not at all dry.

[@franciscojavierfuentes9826]

I think @mrQuckLine was being sarcastic here

[@MrQuickLine]

@@franciscojavierfuentes9826 😏

[@GilesBathgate]

See y'all call it drywall, when clearly its called plasterboard.

[@atomicsmith]

@@GilesBathgateTechnically, plasterboard is a different product than gypsum “sheet rock”. In the UK these types of products are known as “dry lining” which is very similar to the term “dry wall”.

[@MatchaMakesThings]

These are great. Thank you for doing testing. I always figured they were pretty strong, but good to know some numbers on it.

[@D4rkS7der]

Now I would love to see comparison to machine screws

[@TheMrJaagoo]

If the screw snaps as opposed to the thread stripping like it did, then it's only a function of the screw's yield strength and cross sectional area of the thread. A slightly thicker M4 screw would have to hold about 620 kg minimum to qualify for grade 8.8. Or a bit thinner M3 about 360 kg.

[@feedbackzaloop]

For those you simply need to check corresponding standards.

[@TheMrJaagoo]

@@feedbackzaloop Sure, calculating was just more convenient for me than finding the right standard.

[@feedbackzaloop]

@@TheMrJaagoo you still need to know yield stress for a calculation. So if one has to look up something, let it rather be the final number.

[@TheMrJaagoo]

​@@feedbackzaloop You see, the neat part is that here in yuropstan you don't have to look up the strength, it can be read right from the grade. The first number states the the minimum tensile strength and the second the yield strength as a percentage of tensile strength. For example, grade 12.9 means that the material's tensile strength is at least 1200 N/mm^2 and yield strength at least 90 % of that. And if you did, it would still be much faster to find the tensile strength than a table for screw strength with no safety factor baked in and in force rather than torque for small screws.

[@reishin3173]

is there a way for you to rig it to measure the shear force of the drywall screw? it would be interesting to have a comparison between the shear force and the pulling force.

[@ShowAndTool]

This!

[@wifidon6617]

The more you know! Thanks again Matthias!

[@clarkdouglas6517]

Matthias tests stuff no one else would think to test BRAVO!

[@nasonguy]

Working with low voltage and telecom closets I deal with the need to mount a lot of things to various materials, OSB, sheet steel, and thicker steel racking and door frames. When I started I was pretty surprised that my trainer/coworker used the humble drywall screw for everything. I mean EVERYTHING. Over the years I've become a convert, and this video does nothing but reinforce my bad habits, haha.

[@jameshisself9324]

I think your applications are perfect for the humble drywall screw. I've stated pretty strong objections to his implication that metal to metal is great when it so very much is not for a variety or reasons. My home network closets use them a lot. 👍

[@boots7859]

LOL, just imagining you install some old Cisco 4500/6500 or more modern equivelents, or UPS with drywall screws........ 5/10/50K$ worth of equipment supported by the cheapest screws one can buy....

[@nasonguy]

@@boots7859 Ah no man lmao if it’s wall mount that shits getting lag screws. I always push for relay racks though. But cameras, sensors, amps, what ever little junk, it’s getting the drywall screw treatment.

[@ErgoCogita]

They work surprisingly well through moderate shear load as well. I paneled and shelved a handful of E series vans years ago with them and they’re still on the road and holding strong.

[@TWX1138]

This tracks with an experience when I was a kid. Dad put up a fence that was a combination of "wrought iron" square tube (probably just mild steel really) and some engineered fiberboard panels. The vertical posts were set into the ground with concrete footings but the horizontal rails were attached to the posts with right-angle brackets and self-tapping Philips-head screws, and likewise the steel pickets were attached to the rails with the same screws. The fiberboard pickets between the steel pickets were also held on with those same screws. Even as a small child I was able to help move material around, it was all fairly thin gauge, probably 1/16" wall for the pickets, possibly something slightly thicker for the rails, and something more like 3/16" wall for the posts. 30 years later driving past the old house that had changed hands several times the bones of this fence were still there, the metal parts were still the same. The fiberboard pickets had been replaced of course, they were pretty bad even from the outset, but even with heavy winds this solution was holding up just fine.

[@johnpurcell7728]

In my experience, drywall screws are very strong in tension, but weak in shear shock due to hardness. I had some wooden Christmas decorations held onto wooden stakes with drywall screws. About three whacks with a hammer driving stakes into ground and drywall screws sheared. All of them. Repeatedly.

[@technoman9000]

Yep I've had many a drywall screw snap off when hitting a knot in a stud as well. They aren't really designed to withstand much abuse.

[@bullfrogpondshop3179]

Same experience here

[@Gunbudder]

I'm not surprised they are working for sheet metal like that because their shape and threads are similar to sheet metal screws. As far as i know, the only major differences between drywall screws and sheet metal screws has to do with the manufacturing and metals used. sheet metal screws are so cheap though (i have probably 1000 of them lol) i would have never thought to use drywall screws. also i tend to prefer self drilling screws that use a hex head because they are so much easier to drive through sheet metal. its cool to see that drywall screws work though, i would have never thought to try that

[@surapurna]

We using the same screw for carving on PVC pipes cut the top and make a grove on the tip of the screw. Works great and cheap

[@vandenpiaff]

Super useful information. Thanks Matthias.

[@phantom21629]

That's awesome and actually makes sense. Drywall screws are very hard and if you have ever ran them in hard wood, you've likely experienced them snapping the heads off. this is because they are so hard and brittle, like a grade 8 bolt. I use Tapcons in steel power poles when I'm putting riser guard on when we are out of self tappers. They work great.

[@huckbeduck]

Drywall screws make great center punches as well! They stay needle sharp for several strikes & if they get too dull for center punching, they will still be plenty sharp enough to use as sheetrock screws.

[@edheide7229]

More education from you as always thank you again. I hope you have a teaching job.

[@jmtx.]

Amazing rest results. Definitely something to be said for using hardened screws.

[@user-go9hb4td8j]

Thank you. Excellent and interesting report. 👍👍

[@BarneySaysHi]

Flippin' HALF A TON on a drywall screw! Incredible!

[@PaulG.x]

I used a square drive drywall screw to make a valve clearance adjuster tool for my Suzuki motorcycle. The adjuster screws had a square head that was close enough to a square drive bit

[@moore9709]

Small error at 0:16 reading 5/64" for the imperial scale. 3.5 mm is ca. 9/64", as is correctly shown on screen when the pilot holes are being drilled. Very nice video, I like the format.

[@Nono-hk3is]

Matthias, could you design a test scenario that could find the optimal pilot hole diameter? It needs to fond the balance between the risk of snapping the head under high torque vs the resulting linear clamping force/holding strength once the screw is driven in. Smaller diameter pilot risks beheading the screw, but presumably gives higher clamping/holding strength. I imagine that the sweet spot also varies with the some friction coefficient of the material being screwed into.

[@Ammoniummetavanadate]

Usually for a threaded connection there is a defined major and minor diameter. Usually 50-75% of the height of the thread depending on the substrate material. For steel you generally use 50% but given the coarse pitch of drywall screws you probably aren't getting three threads of engagement and would want to go more towards 75%

[@GabrielWB]

Weird to think that I theoretically am able to lift my car mounted on two drywall screws.

[@acmhfmggru]

Test it.

[@tullgutten]

Your load testing machine just continues to impress me, and that you wrote the whole program for it even more 👍🏼😁

[@mickdog2]

quite impressive. you're a real scientist!

[@davidt8438]

I never dreamed a fine thread drywall screw would have a similar holding power of a grade 8 bolt! Good test.

[@matthiaswandel]

Compared to a grade 8 bolt of the same diameter. The grade 8 bolt would undoubtedly be bigger though.

[@pdxRetired]

Nice demonstration. Looks like the drywall screws are a valid option for DIY projects.

[@jameshisself9324]

As long as they are not steel holding steel attached to anything but your house.

[@andrewgalbreath2101]

It's interesting how people will see brittle failure and assume a material is not strong, when it's often the opposite of the case

[@smug_cat1]

500kg on 1 singular screw is wild

[@jameshisself7375]

Yes but you want tough and strong, which proper heat treating will get you. These need to be heat hardened and then another step to temper them. The controls on that for drywall screws is very low standard.

[@kurtlindner]

@@jameshisself7375 Gotcha, I'll use 2 screws per application instead of relying on one. Even inconsistent QC shouldn't affect any individual screw as much as 50% of its strength.

[@custos3249]

Given there's not too much torque applied.

[@jameshisself7375]

@@kurtlindner For wood that would be perfect. For metal there are so many better proper fastener options that take WAY more into consideration than these very simple tensile load tests. Proper bolts have way higher shear strength, plus many other failure modes that this test doesn't consider at all.

[@FailedFace]

Great for pull out strength, is there some material you've posted on lateral shearing force? I'm guessing a bolt will have more, but I'm not sure.

[@timderks5960]

Can confirm. For our parade float (hobby style) this is exactly how we attach wood to metal. It's plenty strong, especially if you plenty of attachment points. I wouldn't use it for something structurally of course, but for something like a floor on a metal frame, perfect. I think I drilled 3,5mm holes for 4mm screws. The biggest issue was keeping the 3,5mm drills intact, since it's not really a drill press kind of situation. I've even had better luck screwing drywall (or just basic wood screws) into metal than self tapping screws actually meant for metal into the same hole size.

[@billj5645]

Very interesting test. When you get into larger sizes of structural tubing they are typically never as thick as they say because the manufacturing tolerance allows a range in thickness. The way the tubing is made the industry has determined that they can shoot for the minimum allowable thickness and always be within spec, and save a few percents of material, so manufactured thickness is always close to the minimum tolerance. Since it is always at the minimum there is actually a "design thickness" used for calculated properties instead of the nominal thickness. I believe design thickness is 93% of nominal thickness.

[@senorjp21]

I like to use drywall screws because they are the cheapest screw you can buy! Maybe the most mass-produced screw? I think the black ones might even be parkerized for corrosion resistance so they don't stain through drywall mud

[@P_RO_]

The coating is black oxide and they do rust if exposed to moisture for enough time. Oxide finishes are actually a form of rust, just used in a more controlled fashion.

[@BlackBaron705]

Very cool! Love these videos!

[@toolthoughts]

good quality drywall screws make a decent universal use fastener, and they're not too expensive. nice to see this sort of testing. 👍

[@jaskaasi]

drywall screws work nice in everything

[@michaellacaria910]

They do rust quickly if unprotected. But, it’s the head that rusts only, the integrity of the joint will still be maintained with or without the head. So if that is not important, then it’s the cheapest screw you can buy. For example, I had to close off the side of the deck so critters wont get in until next year. When I remove them next spring the head will be rusty and I’ll throw them out.

[@eh42]

That has got to depend on brand of screw, no? I would think there are some low cost sketchy drywall screws that will fail at much lower loads. But the thought that I could suspend my car from an overhead hoist with just a couple drywall screws is a bit mind blowing. (Geo Metro scaled at 1,040kg with 1/2 tank of gas and me in the driver seat)

[@matthiaswandel]

but that would leave absolutely no margin of error

[@eh42]

​@@matthiaswandeltouche, I'll use 4 for a 100% safety margin 😂

[@bknesheim]

Some IKEA packs include screws that will only withstand a small fraction of the force Matthias applied. You snap the head off when using them in drywall. 🙂

[@MCsCreations]

Wow... Fascinating stuff, Matthias! 😮 Stay safe there with your family! 🖖😊

[@mmussio]

I have a whole new appreciation for dry wall screws...

[@zweg1321]

Cool Thank you for these interesting test

[@phookadude]

Seems like cutting some groves along a screw to use it as a tap with an even smaller hole might do better as the threads seemed to fail on the edges.

[@Ammoniummetavanadate]

I mean that is just recreating self-tapped metal screws

[@ikocheratcr]

Nice analysis. Also interesting how well your testing rig handless the test forces.

[@johnbowen8917]

You might looking into their self tappers. We used them on the tracks that are 20 gage and the studs are 35. Streakers go fast.

[@ItchyKneeSon]

Wild. Stumpy Nubs, a woodworking channel, also found drywall screws to be very effective fasteners. Their weakness is rust, however.

[@acmhfmggru]

That's why North American vehicles are made using drywall screws.

[@LeesChannel]

😂

[@debluetailfly]

Wish they were instead of all the plastic fasteners!

[@LeesChannel]

@@debluetailfly or double-sided tape

[@jameshisself9324]

WORD

[@Smallathe]

Very impressive test!

[@dfgyuhdd]

They make self tapping fine threads for commercial construction that you might not be able to find at the big box stores. They're awesome.

[@MDealer]

The drywall screws are nice, apart from the missing torx drive and them instantly rusting at the slightest touch of humidity.

[@2centsam927]

Yup. In a pinch you can use Deckmates too.

[@UtahDarkHorse]

Not a pro, so this is just a big, fat theory, but I think the material that drywall screws are made of is hard enough that they are somewhat brittle and stand a chance of breaking when bent, similar to a drill bit. If that's true, they're weakness mey come from lateral shear force or bending forces. A self tapper made of a bit softer material may stand up to those type forces better. would love to see it tested. Thanks for another great video.

[@danielrogers997]

What is the point? They are super brittle if you apply the force to the side. What are you securing with this?

[@mikedimaio1237]

Great test, glad to see you are back at it.

[@skydyverjym]

You do some of the MOST interesting stuff on all of yourube

[@chamonix4658]

love how sharp drywall screws are

[@P_RO_]

More than a few times I've stuck one on the end of a screwdriver and used that as a center-punch. And more than once I've had one of the nasty-sharp beggers stick into my skin when trying to get screws out of a pouch or box.

[@phizc]

A comparison with M3 or M4 (or similar imperial sizes) in tapped holes would have been cool! My gut feeling is that the drywall screws might be stronger. Impressive results.

[@GyprockGypsy]

It's the thread pitch that's most important. Tight threads for steel, loose threads for wood.

[@realamerican6101]

I have done that before but not the testing stuff. Add something else I do if I have a hard time getting a nail in some would use a pilot hole that smaller of course.

[@GoblinKnightLeo]

That's wild - imagine the load on the tiny cross-section of those screw threads!

[@victorhopper6774]

a new way to pull teeth. drilling the pilot hole might be a bear

[@mr.bennett108]

Ahh, the humble drywall screw. I can't say I'm surprised at how well it held up. It IS just a coarsely-threaded piece of hard, mediocre steel. It's honestly probably got a pretty decent shear value as well (I've seen on the internet it might be on the order of 100-150kg/screw), so it really IS just a very useful screw, whether it's used for drywall or not!

[@KRich408]

Pull force is excellent on drywall screws because they are so hard but sheer strength is really bad. I wouldn't use them to hold heavy pictures or shelving. They will snap.

[@bmxscape]

you must have some really big paintings, they can support over 100 pounds of shear force.

[@BrokenLifeCycle]

​@@bmxscapeIn general, shear strength is around half the tensile. But in a lot of applications, that shear load isn't pure shear and is actually a cantilevered beam.

[@bmxscape]

@@BrokenLifeCycle so are you arguing *for* or *against* the statement that a screw can hold up a painting

[@BrokenLifeCycle]

@@bmxscapeI'm arguing that 100lbs of shear force. Most applications aren't pure shear, and that's why these screws suck.

[@bmxscape]

@@BrokenLifeCycle i hope you are joking... theres a test here on youtube called project farm that shows these same drywall screws being tested. two screws withheld 1000 pounds of force in a real world test scenario, with one of the screws breaking. i think even you could pull together the math to see one screw can support far more than 100 pounds. don't take my word for it though, go look it up yourself

[@stellamcwick8455]

I remember when drywall screws were first introduced, everyone thought they found some magical cheat code to avoid using a nail….. good times..

[@wobblysauce]

Tyre shops haven't been the same since.

[@johannes.f.r.]

The other end of the spectrum is also fascinating, people repeating things from the 70s when you use a construction screw.

[@A_Stereotypical_Heretic]

I don't really know of any instance that you'd need to use a nail rather than a screw other than the ones with plastic washers for holding down roofing underlayment. Other than that, nails can be universally replaced.

[@stellamcwick8455]

@@A_Stereotypical_Heretic , depends on the screw. There was a fad in the early 80’s where people were using drywall screws to a build a wood stud wall and attach exterior sheeting when building a shed or a house. Only to have to hear the screws snap and break for the next 10 years when the structure would inevitably move and settle. Nails are still effective when you want a joint to have some flex.

[@P_RO_]

@@A_Stereotypical_Heretic In testing wood framed walls for wind resistance it has been found that toe-nailed studs hold better than any other directly applied fastener. They also perform much better when partially pulled out. Nails are often good enough, faster, and cheaper to use so they're not going away anytime soon.

[@rakeau]

I’d guess the tested absolute limit of a drywall screw, being on par with the rated strength of a proper bolt, the bolts can probably go way higher due to safety factor.. But still, point remains that a drywall screw is probably more than strong enough to cope with whatever loads people might need them to hold. I wonder what the perpendicular shear strength is? ie how much weight could you hang off of one.

[@victorhopper6774]

good for 5 year old kids

[@tornadre]

I have been using drywall screws for everything for years. Never had a problem with them

[@bobweiram6321]

"Don't let anyone convince you that you need a buy a special tap for steel tubing..." 😂

[@rickypacheco]

I wonder how it compares with threaded 3mm hole and 1mm thread pitch. My guess is the drywall screw will do better

[@johng.1703]

the self drilling screws are better for tubing. also no need to drill first.

[@renevile]

4:10 at the end where you show the strenght vs a bolt, the screen was blocked by a youtube recomendation video :( thanks youtube.

[@matthiaswandel]

Not for the whole period, just wind back a bit and pause.

[@zumbazumba1]

Yea drywall screws are awesome and cheap too bad they rust quickly.

[@tiger12506]

I like drywall screws, for sure, but one weakness I've experienced often is that they cannot handle moisture. Makes sense, since they are for drywall, lol. Any outdoor applications are surprisingly temporary when using drywall screws.

[@generalzugs6017]

How about a torsion test? Quite a few snaped when trying to tighten them in hardwood.

[@ooltimu]

You should also test the shear force they withstand. I bet bolts are much better at that

[@samTollefson]

"The fail strength is right up there with the strongest bolts." Unbelievable!

[@boots7859]

In 1 dimension. And a second or third movement direction and it'll all come to tears.

[@samTollefson]

@@boots7859 Indeed!

[@rawbacon]

And machine screws/bolts work well in wood.......Years ago I worked next to a Unistrut packaging business and got gallons of mostly 5/16" bolts from them.

[@WonkyStud]

I have drywall screws everywhere in my shop as shop furniture, just using up what you have and don't hang an elephant on them... until I saw this

[@ciphernemo]

The problem with drywall screws is that they are weak when it comes to shear forces sideways. The shaft itself is fairly weak compared to other screws.

[@LeJimster]

I noticed you using dry wall screws on all sorts of projects over the years, so I got myself a couple of boxes and they certainly do come in handy. I'm yet to use them for their intended purpose though, LOL.

[@0j0nn]

I wonder how an m4 or m5 thread would last in comparison, maybe you can do a follow up on that?

[@FishyBoi1337]

Matthias out here doing the science for the masses! I HATE phillips, but every time I reach for a drywall screw, I'm not disappointed so long as I don't strip the head off 😅

[@snocrushr]

How about trying Deck screws or Concrete screws in steel for comparison.

[@YacoGer]

I'm curious about their shear strength now!

[@Nono-hk3is]

I'm surprised the screws are not failing at the head, where the test apparatus is grabbing it (the screw head). That's good, just not what I expected.

[@hipjazzbone]

So, I find that I break drywall screws a lot. Is the problem shear force? Do they have more carbon, and something is happening if they get to hot being screwed in? My screws come from Home Hardware, probably the same as yours, Matthias. What am I missing?

[@TomsBackyardWorkshop]

How I snap those things off in pine?

[@matthiaswandel]

Easy. Deep enough into a hard enough piece of pine and you exceed the strength of the screw. They can only hold so much tension and so much torque.

[@A_Stereotypical_Heretic]

Because rotary torque acts on the screw shaft much differently than vertical load bearing.

[@Nono-hk3is]

When you are driving in a screw, you are being resisted by the friction of the material along the length of screw . The further in you drive it, the more resistance. And the driving torque is concentrated at one end of the screw, so that little bit of screw beneath the head is taking all the load and is likely to fail. Once driven in, the pulling force of Matthias' test is spread along the length of the screw (or at least, the length that is in contact with the material). Also, there's no twisting forces (torque). Torque is more difficult than linear forces for hard materials like drywall screws to resist, I believe.

[@cadguyfrompti]

Question, so I’m having a metal shop built now on a slab. Would you consider using drywall screws to fasten things, such as insulation, etc to the metal frame?

[@matthiaswandel]

I don't know anything about your insulation or how you plan to put it on, so can't answer

[@caseyrevoir]

The instant failure modality in repetitive sheer performance is why drywall screws are dangerous. I see people equate drywall screws to framing nails in sheer performance and it's quite scary. The average person needs to be advised to always use wood screws for everything. Drywall screws are quite brittle in comparison to a wood screw in my general experience. A handrail around the outside on a deck, or shelving for example. Secured with drywall screws, these could yield a cascade failure whereas a nail or deck screw will need a constant or growing force to lean over enough to either break or loose connection to the deck base or wall. A poorly made chair built of simple joints and drywall screws would break a leg joint almost instantly when it got loose whereas a gold would screw would 1st let you know the chair is unsound by bending, and 2nd, if ignored that, eventually tear itself out of the wood before snapping. That said I would probably built most of a set of drawers with drywall screws.

[@FeedMeAQuarter]

I would have loved a comparison of the different thread pitches in the same material.

[@Dusty-Builds]

Is there a way to make a tap for that screw thread? That way the threads might fit better in the hole.