Choosing the Correct Screw Pocket Screw

If you're using screw pockets for joinery in your shop, eventually you're gonna have to put those joints together. When you do so, I really recommend you stick with screw pocket screws as opposed to trying to substitute something else in. And there are some real distinct reasons for doing so. Here on the bench I've got some screws laid out. Some are screws you should use, some are screws you should not use. Let's talk about the screw pocket screws first and their attributes. When we look at this silver screw, this is a screw pocket screw. It's got fine threads down here at the bottom. It's got a thread cutting tip. So part of the deal with that is that when we put screw pockets together, you don't drill into the mating piece, you just drive the screw. So we wanna make sure we're using a screw with it's own thread cutter on the tip so that it can thread its way into that mating piece. Especially true in hardwoods. Now in the screw next to it, we've got another screw pocket screw. The only difference is that it's a different color. Additionally, it's a coarse thread screw. It's still got that thread cutting tip at the bottom. So there'll be different occasions where we'll use coarse versus fine, talk about that in a second. What I don't want you to use are screws like this. These are called bugle head screws. The problem with these is that the bottoms of these heads look just like a splitting wedge. So you can imagine that if we took this shape or the flathead shape, like we've got on this screw over here, still wedge shaped, when that hits the bottom of our screw pocket, it's gonna have a tendency to act like a wedge and split the material. So there's a big difference between the two heads. On the screw pocket screws we've got pan heads and on these more conventional woodworking screws, we've got bugle or flat heads, and those have that wedge shape to them and they're gonna cause the splitting. Now the deal with coarse thread, fine thread is manmade materials versus natural and hardwoods versus softwoods. So as a general rule of thumb, what you'll wanna do is stick with the fine thread screws anytime you're assembling anything in hardwood using screw pockets. So that would be oak, walnut, maple, cherry, a lot of the North American woods, a lot of the tropical woods. If you're assembling manmade materials, so that would be plywood, particle board, MDF, or softwoods like pine, then you'd wanna go with the screw that's got the more coarse threads in it. Again, making sure that you stick with those pan head screw pocket specific screws. Now let's just do one more thing and look at the heads of the screws. Very commonly, these are square drive screws, and because of the angle at which we're driving them, remember those screw pockets go in at about 15 degrees, using a square drive on the square drive head screw just makes it a lot easier to run at an angle like that. And make sure that the tip of the driver stays in contact, stays engaged, with the head of the screw. So the lesson out of all of this is there's a very good reason why screw pocket screws go with screw pocket joinery. The other thing to think about is make sure you're matching the length of the screw to the thickness of the wood that you're working with so that, by running the screw in at an angle, it doesn't accidentally come out the joining face. So make sure you're loading your shop up with screw pocket screws so that you're ready to assemble those screw pockets using the right tool for the right job.