Choosing Screw sizes?

[Brent Wenzl]

Can someone please recommend what size screws to use on 3/4 " oak veneer plywood? I know I need to use 1-1/4" coarse screws , but has anyone had better luck with less splitting using size 8's , 7's or 6's? Also what size should I use going thru the 3/4"plywood to the 3/4" oak face frame.I was planning on using the washer heads on both and using the fine threads going into the solid oak. I am in the process of building some wall cabinets. I am new to this so any input would greatly be appreciated.
thank you Brent

[KregRep]

Brent, good question. As a good rule of thumb, you want to choose your screw based on the material you are screwing into, not the material you drilled the Pocket-Hole into. With use of ¾” plywood you were correct in your screw selection with the 1 ¼” coarse screw. This screw is only available in the #8 style since it is a coarse thread. When you are going from the plywood into the oak face frame you are once again correct in your screw selection. If you are having a lot of problems with splitting in this situation you can switch to the pan head screws which would be a #6. (for everyone else's information, these numbers reference the diameter of the screw's shank) This would be a little easier to drive due to the smaller shank but will not give you quite the same holding power that the washer head screw offers. Also you will have to be careful with the pan head screws. With its smaller head it can try to pull into your pocket hole a bit so make sure you have your clutch set correctly.

From what you have posted it sounds like you really have a good grasp on screw selection and should have no problems using pocket holes in your projects! Good luck, and good woodworking!

-KregRep

[Paul Leenerts]

Brent - I just finished a desk for my wife using 3/4" Baltic Birch plywood and had great luck with #8s. No splitting what so ever. No face frames on the desk project, but I did finished a small project recently that used face frames and I stuck with the 1-1/4" screws. I would highly recommend doing a test fit using some scraps of the same materials you are using in your project before starting on the real thing. Good luck!

[Brent Wenzl]

thank you for your response, I hope everything works out.
Brent

KregRep said:

Brent, good question. As a good rule of thumb, you want to choose your screw based on the material you are screwing into, not the material you drilled the Pocket-Hole into. With use of ¾” plywood you were correct in your screw selection with the 1 ¼” coarse screw. This screw is only available in the #8 style since it is a coarse thread. When you are going from the plywood into the oak face frame you are once again correct in your screw selection. If you are having a lot of problems with splitting in this situation you can switch to the pan head screws which would be a #6. (for everyone else's information, these numbers reference the diameter of the screw's shank) This would be a little easier to drive due to the smaller shank but will not give you quite the same holding power that the washer head screw offers. Also you will have to be careful with the pan head screws. With its smaller head it can try to pull into your pocket hole a bit so make sure you have your clutch set correctly.

From what you have posted it sounds like you really have a good grasp on screw selection and should have no problems using pocket holes in your projects! Good luck, and good woodworking!

-KregRep