Pocket screw question for 17.5mm plywood

[ear3]

I've been commissioned to make these simple hanging box shelves (just basic butt joint carcasse construction with dominoes and glue), but the material I'm using is 17.5mm multiply (11/16").  Since I'm using pocket screws to secure the back of the unit to the bottom, top and sides of the case, I'm wondering what the optimal setting is on the jig, along with screw length.  Is it better to keep it set at 3/4" and use the 1 1/4" screws, or instead set it to 5/8" and use 1" screws.  Or is it 6 to 1 half dozen....

 

[tjbnwi]

Set the bit for 5/8", use 1-1/4" screws.

Tom

 

[ear3]

Thanks Tom.

 

[grbmds]

Set the bit for 5/8", use 1-1/4" screws.

Tom

[member=4105]tjbnwi[/member] Just out of curiosity, why?

 

[tjbnwi]

The bit will leave a little more shoulder, the screw will still have good purchase without poking through.

Edwards plywood combination is 3 mm short of what the 1-1/4" screws are normally used for.

Tom

 

[ear3]

Initial test showed that the 1 1/4 screw was just slightly too long at those settings, and a few of the screw ends  ruptured through.  So I ended up using a mixed setting to get it done -- I went with 1 1/4" screws, set the depth of the drill bit collar for 5/8, but the height of jig to 3/4.

The bit will leave a little more shoulder, the screw will still have good purchase without poking through.

Edwards plywood combination is 3 mm short of what the 1-1/4" screws are normally used for.

Tom

 

[DiscoStu]

I've been struggling with exactly the same thing. I wish Kreg would produce an app whereby you could put in the thickness of your material and it would tell you the settings for the drill and the driver and what size screw to use.

The table leaves me confused as it tells me the material thickness and the jig height and screw size but not the position of the depth stop on the drill bit. I'm sure different combinations could be used. I also wonder if the thickness of the material being joined could be considered as well as the material that is being drilled?

Sent from my iPhone using Tapatalk

 

[GarryMartin]

I have the below chart pinned from the Kreg site. One of the things that I know has thrown people before is that the measurements Kreg notes are for actual sizing rather than nominal. I've included another Kreg graphic that covers that. Hope this helps.

[attachimg=1]
http://kregjig.ning.com/photo/tmwthwfwwt/prev?context=user

[attachimg=2]
https://www.kregtool.com/about-us/news/kreg-tool-tips-joining/always-use-actual-thickness.aspx

You can also obviously buy the Kreg Screw Selector Wheel if that takes your fancy...https://www.kregtool.com/store/c22/kreg-jigreg-accessories/p285/screw-selector-wheel/?source=1781

 

[tjbnwi]

Initial test showed that the 1 1/4 screw was just slightly too long at those settings, and a few of the screw ends  ruptured through.  So I ended up using a mixed setting to get it done -- I went with 1 1/4" screws, set the depth of the drill bit collar for 5/8, but the height of jig to 3/4.

The bit will leave a little more shoulder, the screw will still have good purchase without poking through.

Edwards plywood combination is 3 mm short of what the 1-1/4" screws are normally used for.

Tom

My jig does not have settings/riser blocks for 11/16 plywood. Which jig are you using?

Even my Foreman is marked with only 1/2, 3/4, 1-1/2.

Tom

 

[DiscoStu]

I've written to Kreg and asked them to produce an app to calculate the correct settings. My idea is that you enter the thickness of material you are drilling and the thickness of material you are joining two and the app tells you the setting for the jig, the setting for the drill depth and which screw size.

I think it could be a winner.

Sent from my iPhone using Tapatalk

 

[grbmds]

Greg actually has a "wheel" which does this. I got it as part of some Kreg set I bought at a Woodworking Show. I checked online and it's called the "Screw Selector Wheel". Problem is the price is now $9.99. I don't know if it's worth that, but it has helped me on a couple of occasions in the past. I Dominos more now than pocket screws, but it does seem to be a useful reference.

 

[grbmds]

Greg actually has a "wheel" which does this. I got it as part of some Kreg set I bought at a Woodworking Show. I checked online and it's called the "Screw Selector Wheel". Problem is the price is now $9.99. I don't know if it's worth that, but it has helped me on a couple of occasions in the past. I Dominos more now than pocket screws, but it does seem to be a useful reference.

Sorry, I meant "Kreg" not "Greg".

 

[ear3]

K4

Initial test showed that the 1 1/4 screw was just slightly too long at those settings, and a few of the screw ends  ruptured through.  So I ended up using a mixed setting to get it done -- I went with 1 1/4" screws, set the depth of the drill bit collar for 5/8, but the height of jig to 3/4.

The bit will leave a little more shoulder, the screw will still have good purchase without poking through.

Edwards plywood combination is 3 mm short of what the 1-1/4" screws are normally used for.

Tom

My jig does not have settings/riser blocks for 11/16 plywood. Which jig are you using?

Even my Foreman is marked with only 1/2, 3/4, 1-1/2.

Tom

 

[leakyroof]

I have the below chart pinned from the Kreg site. One of the things that I know has thrown people before is that the measurements Kreg notes are for actual sizing rather than nominal. I've included another Kreg graphic that covers that. Hope this helps.

[attachimg=1]
http://kregjig.ning.com/photo/tmwthwfwwt/prev?context=user

[attachimg=2]
https://www.kregtool.com/about-us/news/kreg-tool-tips-joining/always-use-actual-thickness.aspx

You can also obviously buy the Kreg Screw Selector Wheel if that takes your fancy...https://www.kregtool.com/store/c22/kreg-jigreg-accessories/p285/screw-selector-wheel/?source=1781

  very cool- thanks for all the info.  I didn't know they were offering the 'Dial-a-wheel item either.  [huh]