If you’ve been making picture frames, cabinet faces, or tables in your woodworking shop, then you likely know pocket holes and pocket hole joinery. Most woodworkers consider it the strongest of joints, even more, strong than mortise and tenon joints.
We’ve written about or at least mentioned pocket hole joinery in a number of past articles here on Obsessed Woodworking, including:
- Picture frame joinery, including pocket holes
- Attaching table legs to a table apron using pocket hole joinery
- Screw sizes for pocket holes
- Pocket hole joinery strength for shelving
- Pocket hole joinery and plywood
So, we know a little about pocket hole joinery, pocket hole screws, and more. We use pocket hole joinery in a lot of our own projects, we’ve read the manual carefully, and we follow the charts that come with the jig kits..
In those previous pieces, though, we mentioned the tools used in pocket hole joinery only in passing. Today we want to focus our attention on those tools.
Pocket Hole Joinery
If we’ve used this joinery technique in our project, we no doubt came across the name Craig Sommerfeld. In the late 80s, and as he was taking on a new kitchen cabinet project in his own home, his wife asked him to hide the screw holes from view in the new cabinets. To make his wife happy and oblige her request, he devised the concept of pocket holes as a joinery technique and built the first pocket hole jig.
It worked for him so well he made more jigs and began selling them at woodcraft shows. Success followed, as did increased production, and he was awarded a patent for the Kreg jig in 1990. A cover feature story in Wood Magazine that appeared in a 1995 edition boosted sales. Eight years later, the big DIY store Lowe’s began carrying the jig and other products then being manufactured by Kreg in all of their stores across the US.
The Kreg jig is the standard by which all pocket joinery jigs are measured. Their models range from single hole to three holes offered in multiple configurations, clampings, and kits, with prices starting as low as $15 for a single hole jig and drill bit, to $140 for a three hole jig kit, and even up to $400 for a pocket hole machine.
If you have a Kreg jig and are involved with small projects for your home and friends, you likely have one of the smaller models. But, no matter what model or kit you have, you know its value in your projects. At their price points and ranges, though, they are not so expensive that you couldn’t afford to have more than one to choose from for any particular project – the right tool for the right job, as we say.
Pocket Joinery Screws
Kreg also makes screws to be used with its jigs in joinery tasks. The screws you choose will depend on the wood you are using in your project, and the size of the screws you choose will depend on the pieces being joined.
Pocket hole joints can be used to join 2 pieces of wood together in any configuration: edge to edge; edge to face; and mitered. The wood being joined will determine the type of screw you will want to use:
- Coarse-thread screws should be used with softwood pieces – the threads are deep and aggressive in their grip; and,
- Fine-thread screws should be used with hardwood pieces, as these will not tear the fibers and lead to splits in wood ends.
As for the size of the screws to be used, this will be determined by the pieces being joined. Pocket hole screws come in 4 common thread lengths: 1”, 1 ¼ “, 1 ½ “, and 2 ½ “ and which one you choose will depend on the depth of the hole you are drilling into the first workpiece.
The pocket hole screws come with a square drive which provides for a high torque when the screw is being turned. The flat bottom of the counterbore acts as a good stop for the screw when it has reached its end point, and the pilot hole drilled by the bit guides the screw exactly where it needs to be as it enters the second piece being joined.
Fortunately, Kreg jigs come with a helpful chart that identifies which size screw to use for what dimensional wood you are joining. A couple of examples will help illustrate this point.
- If you’re joining 2 x 4s, with their actual dimensions of 1 ½” x 3 ½ “, you would use the 2 ½ “ screw for the strongest joint;
- If you were joining 1 x 4 lumber, and remembering that the actual dimensions are ¾ “ x 3 ½ “, you’d use the 1 ¼ “ screw.
This information comes from the chart that accompanies Kreg jigs. Be sure to check the chart for your projects to make sure you give the joint enough strength to last well.
The Pocket Hole Drill Bit
The drill bit used in pocket hole joinery is special to the task. It is stepped in shape and size, with a short and narrow width pilot hole drill at the tip, and a flat-bottomed counterbore shaft for the head of the screw.
The pocket hole drilled with this bit accommodates the screw well. The screws are hardened and self-tapping with its wide washer head, and the screw threads are long and deep. They grip the second piece of wood strongly to the first piece and secure a solid joint.
The drill bit has a stop collar that adjusts to your setting needs to ensure the hole that you drill is the right depth for the wood being joined and the screw being used.
Setting Up The Jig
You will want the pocket hole being drilled to stop just short of the edge of the first piece being joined, and exit the first piece at or very near the center point of the second piece. You also want the screw to reach at least the center of the second piece’s width.
The jig takes care of setting the correct alignment for the angled hole needed for a strong joint. Attaching the workpiece to the jig sets that angle up properly for you. This convenience makes using the jig easy and quick, with most of the thinking done already for you.
The pocket holes should be at least a half-inch from the edge of the first workpiece, also. This will help ensure the workpiece will not be split when the hole is drilled and the screw is tightened.
Again, the charts that come with the Kreg jig kits are very helpful in laying this all out for you. As with all tools, reading the instruction manuals that come with them is an important part of good woodworking shop standard practices.
The Final Step In Pocket Hole Joinery
If you are satisfied that the hole will not be visible, no further action is required. However, if the hole might be seen, and you are like Mrs. Sommerfeld and want them to be hidden, you can always use a pocket hole peg. You can purchase these by the bag and snip them to size. A little glue, a little sanding, and then the finish will give a nice appearance to your project.
If you are new to pocket hole joinery, here’s a Pocket Hole Joinery Basics video for you. It’s not too long, but it touches all the right bases for the beginner.
The question asked, then, what tool do you use to make pocket holes, actually should be what tools, plural. Here’s the list:
- Pocket hole jig
- Power drill
- Pocket hole drill bit
- Pocket hole screws
- Pocket hole pegs
You no doubt already have a power drill in your shop, and the remaining tools on that list are inexpensive and won’t break your budget. Your projects most likely already include builds that would benefit from pocket hole joints, too.
They’re easy and quick, offer a strong joint, and the holes can be hidden. What else could you ask for on your next project?