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Kreg Pocket Screw Length

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Forum topic by clin posted 03-07-2016 01:27 AM 670 views 0 times favorited 14 replies Add to Favorites Watch
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clin

510 posts in 457 days


03-07-2016 01:27 AM

Running into a weird one with Kreg pocket screws.

I’ve used them quite a bit for 3/4” material. But I’m now looking to use them for some 1/2” material for the first time. The screw boxes list the screw lengths to use for various material thickness. The screw boxes clearly state to use 1” screws for 1/2” material.

I made some tests, and had problems (see below if you care). This is when I looked at the screw guide label attached to the Kreg K5 drill jig. It says to use 1” screws for 5/8” material, and 3/4” screws for 1/2” material.

Anyone else run into this?

Seems like Kreg is not being consistent. Or perhaps different Kreg drill jigs use different screws. I’m using a K5.

Perhaps I need to go to the 3/4” screws, which I think means I need some micro-pocket adapter thing. Or maybe there is some way to make these 1” screws work by setting the jig up to as if it were thicker material like 5/8”. This would of course mean the screw on’t be as centered where it exists the edge of the material.

Thoughts?

Specifics of what I ran into (if you care).

In my first test, I found the screw head sticking out out too much. These 1” screws already have a smaller head to help avoid this. I figured I needed to adjust the drill depth a little deeper. But as I was afraid of, with the screw head just flush are bit below the surface, the screw comes out the other side.

While the material, 1/2” ply, is like all ply anymore, a bit shy of a true 1/2” thickness, but it is only 10 to 15 thousandths thinner than 1/2”. So it’s actually pretty good. So I do not believe material thickness is the issue. Seems like I need to use the 3/4” screws, but not sure.

-- Clin


14 replies so far

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hotbyte

841 posts in 2437 days


#1 posted 03-07-2016 01:39 AM

I’ve used 1” screws with 1/2” ply in past but with a K4 jig. It has been a while but I don’t recall any major issues using setup guide lines on the jig.

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clin

510 posts in 457 days


#2 posted 03-07-2016 02:28 AM


I ve used 1” screws with 1/2” ply in past but with a K4 jig. It has been a while but I don t recall any major issues using setup guide lines on the jig.

- hotbyte

In your application, is it possible the heads were a bit proud of the hole, but it didn’t matter? Often it wouldn’t, in my case I need them to be flush so they do not interfere.

Also, doing a bit of research, it seems Kreg does recommend 3/4” screws with their micro jig K3, K4, K5 attachment. this is just a smaller diameter pocket hole. Turns out I have one of these and it came with a few 3/4” screws. Seems to work fine. Though I’m having to order the screws.

I also played around a bit with K5 settings. Set it to 5/8” material, which starts the hole further back. But as expected, the exit is off center. I’m using 1/2” Baltic birch plywood. This put the exist hole off center enough to cause the ply to split.

Though it wasn’t way off center. Maybe 1/16”. My guess is these larger, 1” screws (#8 I think), are a bit too big to use in 1/2” ply without risk of splitting.

If it hadn’t split, I’d probably run with these 1” screws using a 5/8” material setup, with drill depth as needed. But I obviously can’t allow for splitting the plywood.

I’ve got some 3/4” screws on order, and I few to play with. We’ll see how it goes.

Project happens to be drawer boxes for shop cabinets. I may just decide to go with the air nailer (as suggested by Tom Clark in his book “Practical Shop Cabinets”). But with pocket screws they would be hidden by the drawer front (thus the need for the heads to be flush), or screws in back where they cannot be seen unless the drawers is pulled out.

-- Clin

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hotbyte

841 posts in 2437 days


#3 posted 03-07-2016 03:34 AM

Hmm…it was shop drawers with false fronts that I did. I truly don’t remember if they were proud of ply or not. I can check the ones on rear of drawer tomorrow.

If they did stick up, I probably just chiseled a shallow relief for them in false front. Another thought would be to file them down flush once installed.

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sawdust703

270 posts in 881 days


#4 posted 03-07-2016 03:51 AM

Clin, I just built a kitchen drawer for a customer using 3/4” birch ply, & put the kreg to use. I used 1 1/4” screws. I didn’t have any trouble w/set up, or screw heads being proud of the drilled hole, or going thru. Are you setting your depth right? If you’re using 1/2” material, x2 makes an 1”. By the time you drill the hole for the screw, & to hide the head, your 1” screw will definitely be to long. You’re needing to go a 3/4” screw to prevent your issues. Hope this makes all makes sense.

-- Sawdust703

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clin

510 posts in 457 days


#5 posted 03-07-2016 04:45 AM



Clin, I just built a kitchen drawer for a customer using 3/4” birch ply, & put the kreg to use. I used 1 1/4” screws. I didn t have any trouble w/set up, or screw heads being proud of the drilled hole, or going thru. Are you setting your depth right? If you re using 1/2” material, x2 makes an 1”. By the time you drill the hole for the screw, & to hide the head, your 1” screw will definitely be to long. You re needing to go a 3/4” screw to prevent your issues. Hope this makes all makes sense.

- sawdust703

I’ve done a lot of 3/4” material myself with the 1 1/4” screws. I agree that 1’ is too long base don what I’m seeing. But what is so weird is all the different Kreg screws boxes, list 1” screws for 1/2” material. That’s what I was going on. Even the box for thew 1” screws, lists it that way. I’ve since looked at some of the jig manuals, and they are show the same thing the K5 does, 3/4” screws for 1/2” material, 1” for 5/8” and so on.

Thought maybe I was looking at something wrong, but it appears that for whatever reason, the screw length tables printed on their screw boxes is just wrong. Or maybe there’s some fine print somewhere, that says that the screw heads will stick out.

-- Clin

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clin

510 posts in 457 days


#6 posted 03-07-2016 05:04 AM

I found more than one bit of contradictory, or at least incomplete, information from Kreg printed material. But I think what it comes down to, is you would use 1” screws in 1/2” material, if what you are joining is thicker than 1/2”, or is perhaps 1/2” material joined edge to edge (like a face frame).

But if you are make a corner out of 1/2”, you go with the 3/4” screws. One bit of Kreg documentation actually says this.

This may explain why the screw boxes say this. Though really, they should elaborate more. I think it’s pretty obvious, that if what you are screwing into is thick enough, you can use as long a screws as you want. So I think the default, should be the quite common corner joint of similar thickness materials.

Anyway, I’ve played around enough with what I have to see there really is no way to do what I want with 1” screws. Short of compensating for the heads sticking out in some way (filing down or creating clearance in the drawer fronts).

It’s not a big deal, I just was surprised by this because of the mis-directions printed on the screw box.

-- Clin

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daddywoofdawg

1010 posts in 1036 days


#7 posted 03-07-2016 09:12 AM

3/4” for 1/2” ply,but baltic birch is really in MM so it’s thinner that 1/2”

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AlaskaGuy

2406 posts in 1770 days


#8 posted 03-07-2016 10:40 AM

The time you’ve spent messing with this Kreg Jig stuff you probably chould have alread made some drawers using a simple locking rabbet joint. That my go to joint for 12mm Baltic Birch plywood.

Yes I use pocket hole for some stuff.

-- Alaskan's for Global warming!

View hotbyte's profile

hotbyte

841 posts in 2437 days


#9 posted 03-07-2016 11:55 AM

And, I’m sure there are some out there that could have hand-cut dovetails before you could get your TS setup. They would also probably never use ply either.


The time you ve spent messing with this Kreg Jig stuff you probably chould have alread made some drawers using a simple locking rabbet joint. That my go to joint for 12mm Baltic Birch plywood.

Yes I use pocket hole for some stuff.

- AlaskaGuy


View Redoak49's profile

Redoak49

1944 posts in 1450 days


#10 posted 03-07-2016 12:02 PM

I made some drawers and used the Kreg Micro jig and followed the instructions. It worked well but you have to make certain not to over drive the screws.

I had much better luck with the micro jig rather than the regular one.

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hotbyte

841 posts in 2437 days


#11 posted 03-07-2016 12:29 PM

Memory is an odd thing…While I had the dogs out this morning, I checked the rear of a drawer. The screw head is totally visible, i.e. it is not down inside the pocket, and does sit proud of the surface just a smidgen. NOW, I do recall the screw heads being a little proud of surface and having to chisel a small relief area for them.

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clin

510 posts in 457 days


#12 posted 03-07-2016 05:06 PM


3/4” for 1/2” ply,but baltic birch is really in MM so it s thinner that 1/2”

- daddywoofdawg

I had already noted that earlier in the thread. My material is only 10 to 15 thousandths thinner than a full 1/2”. Which seems a bit odd, as that works out to be 12.3 mm. So I don’t know what it is supposed to be 12 mm or perhaps 12.5 mm. In any case, it is between 0.485” and 0.490”.

As I also mentioned, I did find some Kreg info saying 3/4” screws for screwing 1/2” material to 1/2” material (what I’m doing) and use 1” screws for screwing 1/2” material to 5/8” or thicker.


I made some drawers and used the Kreg Micro jig and followed the instructions. It worked well but you have to make certain not to over drive the screws.

I had much better luck with the micro jig rather than the regular one.

- Redoak49

Since first posting this, I realized I had bought the micro-jig when I bought the K5 and gave it a go with the sample 3/4” screws. Works just fine.


Memory is an odd thing…While I had the dogs out this morning, I checked the rear of a drawer. The screw head is totally visible, i.e. it is not down inside the pocket, and does sit proud of the surface just a smidgen. NOW, I do recall the screw heads being a little proud of surface and having to chisel a small relief area for them.

- hotbyte

Memory, what’s that. I think I used to have one of those too, but now I don’t remember. I’m only in my mid-50’s. Hate to think what I’ll be like 20 years from.

It’s actually good to know that you were getting the same results I got with the 1” screws in 1/2” material. Heads are only just a bit proud. I also thought I might just create clearance in the drawer fronts. But I’ll be going with the 3/4” screws. These are also smaller and I think less likely to split the plywood. Of course I need to watch the torque when driving the screws.

-- Clin

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hotbyte

841 posts in 2437 days


#13 posted 03-07-2016 05:27 PM

I’ve not looked at their micro jig but sounds useful for thinner applications. I have the larger HD version for doing 2X material and it is nice to have. The screws aren’t much longer than the longest for standard jig but much thicker/heavier shaft.

View clin's profile

clin

510 posts in 457 days


#14 posted 03-07-2016 05:48 PM



I ve not looked at their micro jig but sounds useful for thinner applications. I have the larger HD version for doing 2X material and it is nice to have. The screws aren t much longer than the longest for standard jig but much thicker/heavier shaft.

- hotbyte

I also have the HD. Haven’t used it yet. But thinking I might make use of it for some yard gates I need to make this spring.

-- Clin

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