# How to screw into the edge of plywood?



## blackthumb (Apr 10, 2008)

I know there must be some way to do it, what is the best?


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## GaryK (Jun 25, 2007)

Drill a hole and glue in a dowel, then drive your screw into that.

Make the dowel as large as you can.


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## DovetailNJ (Mar 19, 2008)

Use confirmat screws, they're designed for that purpose.
You'll need to pre-drill for them, but they work well.
Hafele sells them.


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## Mershon (Apr 4, 2008)

the dowel works well for a tougher joint. I think the secret is to not overtighten it. Definately predrill and drive the screw by hand…..Trya screw with a big bite as well like a sheet rock screw or similar


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## blackthumb (Apr 10, 2008)

Yes, the dowel idea sounds good. What about screwing into composition wood or particle board?


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## wooddon (Jul 11, 2007)

Drill a pilot hole and squirt in cyanoacrylate glue. It will provide a good grip.


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## jimc (Mar 6, 2008)

I don't know if GaryK was referring to drilling a hole into the edge and inserting a dowel or drilling from the side and inserting a dowel. For me, the best way, if the project allows it, is to drill through from the side insert the dowel, drill a pilot hole and screw into the side of the dowel rather than the end grain. Either way will work but you get a lot more strength inserting the dowel so that you aren't screwing into the end grain of the dowel.

JimC


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## offseid (Jan 16, 2008)

And be sure that you're screwing perpendicular to the grain of the dowel too.


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## blackthumb (Apr 10, 2008)

Yes, dowel from the side, how far in from the edge should it be? I imagine a half inch or more.


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## Newbie17 (Feb 20, 2017)

For what it's worth I just did a test because I wanted to know the answer as well. Using a Kreg softwood/plywood coarse thread self-tapping 1 1/2 inch screw, I fastened together two pieces of 3/4" baltic birch plywood butt jointed at 90 degrees to each other. The side with the head of the screw touching it was predrilled halfway through the plywood because I was simultaneously testing a plug cutter. After inserting the Kreg screw, I checked for bulging plywood and myself and wife detected zero "hump." Then I tried to pull the plywood pieces apart as hard as I could and it didn't budge. Determined to make it fail, the I folded the plywood towards each other. The screw still didn't pull out, but eventually the screw snapped in half. After the bending pressure to failure, there was a slight hump in the surface of the plywood. So my unscientific opinion is I wouldn't hesitate to screw into the edge of 3/4 inch baltic birch plywood with coarse thread self-tapping screws. I will say that if this were a project I cared about, I'd cut dados and use the screws for increased strength. In fact I'm doing this right now!


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## therealSteveN (Oct 29, 2016)

There are a lot of ways to do it, but if I want it to last I edge the entire side of the plywood, and screw through very hard Maple, or Oak. Take your pick of how to edge it, just make sure to make it thick enough to work.


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## rwe2156 (May 7, 2014)

I've used various screws into ply the only issue is within a few inches of end.

Apply a clamp before drilling/screwing eliminates problem.

I commonly use Spax screws and tapered countersink. Even trim heads spyou would be surprised how well they hold. I use them for attacking bullnose trim to shelves.

Confirmat screws are excellent. I was introduced to them building melamine cabs.

If you go that route be aware the drilling ply you can't punch in like melamine this drill can go a bit wonky if you're not exactly in the middle.


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## bilyo (May 20, 2015)

This thread was started several years ago, but the question still comes up from time to time. My first answer is to not screw or nail into plywood edges if you can avoid it. However, if you must, Robert's comment about putting clamp pressure on the spot you are inserting the screw will work well by keeping the plies from splitting as the screw is inserted. The down side of this is that sometimes you can't get a clamp to reach the spot. In that instance, dowels work or pocket screws may be best.


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## AlaskaGuy (Jan 29, 2012)

I have screw together ******************** loads of cabinet boxes and so have thousand of others. Get good cabinet assembly screws and the right counter sink pilot bit.










Its a shame the bean counters on this site won't let us post pictures big enough to see detail.


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## Newbie17 (Feb 20, 2017)

I hadn't realized how strong dowel joints are until I started down the rabbit hole of researching joint strengths. I have to say, I am disappointed how much weaker the domino joints are compared to a lot of other options, including dowels. Comparisons are one thing, but as long as the joint can withstand the normal forces applied to it, it's strong enough. Have any of you ever heard of a domino joint failing in a finished project? AI'm debating on whether or not to get a dowel jig for more strength demanding joints.

Additionally, I have furniture from college held together by staples through mdf and the dressers lasted 15 years before the drawer boxes fell apart. The carcass is still solid. The drawer slides were also fixed in place with staples. I kinda laugh-cried after starting the woodworking hobby and realizing how shoddy all the furniture I owned was.


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## Loren (May 30, 2008)

> Confirmat screws are excellent. I was introduced to them building melamine cabs.


I think there's a slightly different spec drill size for plywood and melamine, but as a practical matter, I've drilled both with the same size and had good results.


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## mdhills (Mar 12, 2011)

> I hadn't realized how strong dowel joints are until I started down the rabbit hole of researching joint strengths.


I think they are pretty good for a number situations.
They tended to be the failure point in some of our old chairs, where the dowels had dried out and shrunk relative to the holes and the glue subsequently failed. But chairs are one of the more extreme joint testing situations.

Matt


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## CrankAddict (Dec 10, 2018)

> Its a shame the bean counters on this site won t let us post pictures big enough to see detail.
> 
> - AlaskaGuy


+1000


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## AlaskaGuy (Jan 29, 2012)

> Confirmat screws are excellent. I was introduced to them building melamine cabs.
> 
> I think there s a slightly different spec drill size for plywood and melamine, but as a practical matter, I ve drilled both with the same size and had good results.
> 
> - Loren


+ 1…...I have done the same thing many times. However considering the cost of the special drill bit and the cost of the comfirmat screws go with cabinet assembly screws for plywood (no drywall screws please). The comfirmats do work well in melamine.

BTW the comfirmat come in different sizes, One size for 3/4 plywood and one size for 1/2 plywood.


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## therealSteveN (Oct 29, 2016)

In a thread titled…..

"How to screw into the edge of plywood"



> I know there must be some way to do it, what is the best?
> 
> - blackthumb


Looking at this thread it has a lot of entries about the plywood being screwed together as a cabinet. You don't actually state what the screwed together plywood is going to be. Many of the answers given will fail if these pieces of plywood aren't then attached firmly to a wall, and Sistered to others of their kind.

Probably long ago, someone should have asked whatchabuilding????

It will make a difference.



> Its a shame the bean counters on this site won t let us post pictures big enough to see detail.
> 
> - AlaskaGuy


I would think detail can be shown if the photographer keeps the allowable sizes in mind when taking the picture. The one given as an example is so far away, and no specific area of it is localized to show much. Much less detail. I think it's a cabinet on it's side, with maybe a sander sitting on top of it? Not sure though.


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## AlaskaGuy (Jan 29, 2012)

> In a thread titled…..
> 
> "How to screw into the edge of plywood"
> 
> ...


This photo showed great detail before I uploaded to the forums software. You could see every pencil line and every screw head. It clearly showed you can easily screw into the edge of plywood. After going through the forum software you can't see those pencil lines and screw head so much.

As far a being far away with the camera, its pretty tough to get closer when you no longer have possession of the the cabinet. I suppose I should remove the sander, the trash can and the dust collector too as not to confuse anyone about screwing into the edge of plywood. Heck someone might think I was try to should how to dump and dust collector into a trash can.

Not being very good a writing I try to use picture as much as I can to help explain my point. I often use what ever photos I have on hand. If its not clear to the OP he can ask specific question. It its not clear to you that's OK because you're not the person who asked the question.


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