A pocket-hole joint can provide a fast and reliable method to join wood together. A pocket hole is drilled at a precise angle and depth to create a pocket for a flat-head screw. The pocket screw connects the two pieces of wood, and when used with glue, it forms a strong, permanent joint. The joints are easy to make when using a jig system, even for a DIY’er, but the task first requires setting up the tools.
Here are the three main components of a pocket-hole jig:
Guide block: The pocket-hole jig has a block that guides a step drill bit into the wood at a specific angle to produce the engineered hole to house the screw head. The block is adjustable and should have its drilling depth set according to the thickness of the boards to be joined.
Step Drill Bit: The “step" drill bit is so named because it drills in two steps. The bit has a shoulder that bores a large hole to fit the screw head while a narrow center tip to bores a smaller hole for the threaded screw. To accurately stop the drilling depth, a stop collar must be tightened (using a set screw) onto the bit shaft. The setup of the pocket-hole jig will determine where to position the stop collar on the bit.
Pocket Screws: Pocket joints require pocket screws, which have a flat underside head to give clamping pressure to the wood. These case-hardened screws are designed with self-drilling tips that will not split the wood when driven in. The self-tapping screws also eliminate the need to pre-drill the second piece of wood. Note that it’s important to choose the appropriate length of screw based on the thickness of the boards you intend to join.
Once you’ve set up the jig, the rest is easy. To make the joint, first clamp the jig in position where you want to drive the screw, then drill the pocket hole with the step bit.
Next, apply wood glue to the joint and clamp the mating boards in position. Use a long driver bit (included with the jig) to drive the pocket screw into the hole, completing the joint. There's no need to wait for the glue to dry before continuing with your project.
After a little practice, even novice woodworkers will get the hang of making these strong wood joints to build bookshelves, tables, cabinets, chairs and more.
How to Set Up a Pocket-hole Jig
In my experience, the trickiest part of making pocket holes is the tool setup, because it requires consulting the instruction manual for specifics for each project.
Step 1: Use the thumb screw to align the drill-guide block with the marking that indicates the thickness of the material being drilled. If you’re about to drill through a 3/4“ board, align the block at the 3/4“ mark.
Step 2: Refer to the instructions that came with your jig for details about setting the step bit’s stop collar in relation to the jig setting. For example, the instructions for the Kreg Jig shown in blue instructs that if the jig is set at 3/4“, the stop collar should be set at 3-9/16“ from the shoulder of the drill bit. Tighten the collar’s set screw with a hex key.
Step3: Select the appropriate screws. Choose from coarse or fine threads to suit either soft or hardwoods. Screw length is critical. The jig’s instructions will offer specific suggestions. For example, the Kreg instructions recommend using a 1“ screw to join 1/2“ material to 1/2“ material. To join 1-1/2“ to 1-1/2“ material, Kreg recommends using a 2-1/2“ pocket screw.
After your tools are set up, you’re ready to square up the boards in the jig, clamp everything in place, and drill your pocket holes. Once the pocket holes are drilled, you’ll be ready to drive screws and assemble your project.
Using the Auto-Jig from Armor Tool
Okay, see those detailed steps and references to instructional manuals that I list in the section above? That method works just fine, but some mad genius at the Armor Tool company came up with a device that automates all those steps in a single fluid motion.
As you clamp the board to be drilled into the Auto-Jig, several things happen at once: The wood squares up and is held securely for drilling. The drill block rises to and remains at the appropriate jig setting based on the thickness of the wood being clamped. Furthermore, a collar-holder on the step bit (which is mounted alongside the Auto-Jig platform) slides the collar to the appropriate stop position, ready for you to tighten it in place. Lastly, the color chart on the side of the drill block matches Armor Tool’s color-coded pocket screws, so you can tell at a glance which screw to grab for the project.
In other words, the Auto-Jig combines all the individual setup steps into a single step activated by the press of a lever. In doing so, it eliminates the need to keep referring to a manual, saving time and frustration. If you get into pocket-hole joinery, I recommend picking one up.
Check out this demo video: