Pocket hole joints are no newcomer to furniture construction. For decades, commercial manufacturers have relied on this type of joinery for super-quick and efficient assembly. Next time you’re at your local furniture store, look inside a cabinet or under the frame of a table. Chances are you’ll see pocket screws at every corner.
More recently, this type of joinery is finding its way into the homes of DIY wood project builders. That’s largely due to the pocket hole jig, which is now available in just about any store that sells woodworking or building supplies.
At first glance, a pocket joint resembles a simple butt joint – no groove, dado, rabbets, or other fancy joinery – just two boards stuck together end to end. However, a butt joint by itself is a relatively weak woodworking joint, and usually requires some type of hardware or fasteners to make it work. That’s where pocket hole joints come in. Using a special jig, builders drive a pocket screw through the edge of one board and into another (usually at 15 degree angle). This creates a surprisingly strong and durable joint between two project pieces, and in many cases, does not require glue.
In addition to its remarkable strength, the joint also offers the following great benefits:
–No complicated joinery skills. Perfect for beginners.
–No fancy woodworking tools. Use an inexpensive power drill/driver and a pocket hole jig.
–No glue required. The joint is strong enough to leave as is without gluing.
–Joints Completely Hidden. Holes can be easily hidden with plugs to cover the screws.
Basics: What You’ll Need:
–6″ Square-head drive (#2)
About the Kits
Some kits include several of the items listed above, particularly the special drill bit and the square head drive for your drill. Some kits also include clamps, although I prefer using my own. Kits might also include some wood plugs for concealing the joint, but usually not enough to complete a large project.
Pocket Hole Screws
If you’re wondering if you can skip buying the special pocket screws – and just use whatever wood screws you already have in the shop, the answer is no. Well, almost no anyway. I have seen some styles of cabinet screws that are very similar, and would probably work in this type of joinery. However, since I usually have to go out and buy new fasteners for every project I build anyway, it’s just as easy to buy the pocket screws, which usually come in a wider variety of sizes anyway.
Pocket screws have two unique features that typical wood screws don’t – (1) a self-tapping auger point, which eliminates the need for a separate pilot hole into the board you are joining, (2) a flat, washer-style head that seats firmly in the bottom of the pocket. When shopping for these types of screws, you’ll have a few choices to make in which style and size to buy.
Which Thread? Fine vs Coarse
As a general rule of thumb, use fine-threaded screws for hardwoods like oak, cherry, and maple – and coarse-threaded screws for softwood like pine and poplar. A fine thread means the screw goes in slower, which makes the screw less prone to break. Plus, the shank is also thicker, which also helps prevent a broken screw.
Breaking screws is not so much an issue with softwoods and plywood, so use coarse-threaded screws for these types of materials. Coarse-threaded screws drive in much faster, and are easier to use overall. However, be careful to avoid driving the screws in too far.
Head Style. Use pan head screws for hardwoods, and washer head screws for plywood and pine.
Screw Length. The right pocket screw length depends on thickness of the boards you are joining. One of the most common uses of pocket screws is to join 1x boards (1x4s, 1x6s), so you’ll always find a good supply of pocket hole screws made specifically for this type of lumber. However, other sizes are available for different size boards (Kreg Tool offers nine different lengths of pocket hole screws).
For outdoor projects, you’ll need pocket screws that are treated with a protective coating, something similar to what you’ll find in the Kreg SK03B Kit.
Clamp, Drill, and Drive – Pocket Hole Joinery in 3 Easy Steps.
The best part is the easy process, which can be narrowed down to three simple steps.
1. Clamp the Jig. Your first job is to align the jig on a board (where the screws will be located) and clamp it in place. Most pocket hole jigs include adjustable guides and runners to help you get the jig aligned exactly where it needs to be for a particular size board.
2. Drill the Pilot Hole. Most kits include a special bit for drilling the pilot holes (an ordinary drill bit won’t work). The unique design allows the bit to leave a small “pocket” at the entrance, where the head of the screw will rest after completing the joint. The bit should also feature an adjustable stop collar, which controls the depth of the pilot hole. Be sure to check your instructions to find out how to set this ring to match your board thickness.
3. Drive the Screw. After drilling the pilot hole, remove the clamp and jig from the board. Then take a quick look to see if the pocket holes are the right depth, and in the right position. This is also a good time to clean up any rough edges the bit might have left behind.
Which Board Gets the Pilot Hole?
Because of the self-tapping feature of pocket screws, we only need a pilot hole in only one of the boards we are joining. So which board gets the pilot hole? As a general rule, it’s better to drive screws into the side of a board (against the grain), rather into the end of a board (with the grain). This is especially true for self-tapping wood screws (like pocket screws), which have a tendency to split boards if they are driven into the end grain. After you have decided how you want to assemble your project, note where the edges and ends come together and plan your pilot hole locations appropriately.