Pocket holes and pocket hole joinery are no strangers to us at Obsessed Woodworking or to these pages. We love our Kreg pocket hole jig, and we use pocket hole joints in many of our woodworking projects – cabinet doors, picture frames, desks, tables, and other furniture. They make a strong joint, and with the pocket hole jig, they are easy and fast.
The Kreg jig makes it easy and an almost no-brainer for drilling pocket holes. Set the jig, set the drill guard for depth, drill the pocket hole, and join the two workpieces together with pocket hole screws. The jig kit comes with a measurement chart that tells us the drill depth and the pocket hole screw size to use for the joint, and we simply need to follow the guidelines.
We’ve written about pocket holes and pocket hole joinery many times in the past on these pages, including here, here, here, and here. We’ve answered questions about using pocket holes with plywood, whether pocket holes are strong enough for shelving, and the size of screws to use.
The one question we do have to consider that those charts do not necessarily answer is the distance between the pocket holes. But before we answer that question, let’s make sure we’re all clear about pocket holes and joinery.
What Is Pocket Hole Joinery?
If you’ve made a picture frame, a cabinet door, or added a vanity plate to a table project, it’s likely you used pocket hole joinery to create that strong joint. You’ve drilled angled pocket holes in a piece of wood and used pocket screws designed specifically for the purpose through those holes and into the second piece of wood to draw them together into a strong joint.
A jig used for that drilling was originally designed by Craig Sommerfeld in the late 1980s. He was about to build new cabinets for his home, and his wife asked if he could hide the screw holes in them and their doors. His answer – the pocket hole – led to the invention of the pocket hole jig, which in turn led to the Kreg jig, a patent awarded in 1990.
Wood Magazine carried a picture of the Kred pocket hole jig in 1995, and suddenly sales skyrocketed. Eight years later, Lowe’s began carrying the Kreg jig and other products the Kreg Tool Company manufactured – solutions for joining, cutting, clamping, and more.
The Kreg jig is the standard by which all pocket hole joinery tools are measured. It comes in a variety of models, from a single hole to three-hole versions, and prices begin for the single hole model at around $15. Pocket hole machines used for mass production can run up to around $400 for commercial uses.
Pocket Hole Screws
Kreg also manufactures the pocket hole screws used in joinery. The screws used in any particular project will depend on the wood, and the size of the screws will depend on the size of the pieces being joined.
Pocket hole joints can be used to join wood in any configuration:
- Edge to edge
- Edge to face
The type of screw you use, as we said, depends on the wood you are using for your project:
- Coarse thread screws, used with softwoods, have deep threads that hold aggressively; or
- Fine-thread screws, used with hardwoods, will not tear the wood fibers that can lead to splits in wood ends.
The pocket hole screws come in sizes that range from 1” up to 2 ½ “, and the size you use is dependent on the depth of the hole being drilled.
Pocket hole screws come with a square drive to allow a high torque when the screw is turned. The flat counterbore stops the screw when it reaches its end point, and the pilot hole drilled by the bit guides the screw to the exact depth it should be in the second piece being joined to create the strong joint pocket hole joinery is known for.
Kreg’s helpful chart that accompanies every jig kit identifies the right screw for the job based upon the dimensional wood being joined. All you have to do is follow the chart for the strong joint your project needs.
The only question the chart doesn’t answer is any guidance on how far apart the pocket holes should be.
New Jigs To Measure Distance Between Pocket Holes
Just as Craig Sommerfeld solved the way to hide screws and screw holes in cabinetry for his wife, and Kreg has developed the jig and other joinery solutions, Kreg has also addressed the question of how far apart those pocket holes should be.
Wanting to answer the frequently asked question what determines the best spacing between pocket holes, Kreg has developed new features into the drill guides on the pocket hole jigs that make pocket hole spacing. As you might have guessed, it is based upon the width of the boards being joined or the size of your project.
One of the advantages of using pocket hole joinery is that it does not need to be exact. There are no pilot holes in the piece being mated; it pretty much doesn’t matter if there is a bit of variation in where you drill the holes.
The hardened steel drill guides in Kreg jig models now offer hole-spacing options for you to choose from in your joinery. On models with multiple drill guides, the spacing between the drill guide holes is not even.
The Kreg 720, 720 Pro, and the 520 models all have three drill guide holes, unevenly spaced, to allow multiple choices on where to drill. This means it will not be necessary to change the jig setup between drilling.
The Kreg 320 differs in that it has a spacer between its 2 drill hole guides. The spacer is removable, so it is easy to change the distance between the 2 holes without having to change the jig setup between drillings.
These innovations eliminate the necessity of both moving the jig setup and even the need to do any deep thinking. The choices have already been measured for you, and you simply choose which one best fits your project.
Board Width and Material Dimensions with Pocket Hole Joinery
The built-in features of these Kreg jig models are used when joining edge to face, such as when building a frame for a picture or mirror. You’ll be using the pocket holes at the end of the board as it is joined to the face of the second piece.
The pocket hole spacing on that piece end will be determined by the width of the board.
If you are using a model 720, 720 Pro, or 520, you would choose the two drill guide holes closest together (these models have 3 drill guide holes, a single hole on one end and double holes close together at the other end) for a narrow piece of wood such as a 1 x 2, or a 2 x 2.
If you are using a model 320, the two-hole jig that uses a spacer, you would simply remove the spacer so the drill guide holes were close together and within the width of those wood pieces.
When the wood pieces in your project are larger, perhaps 1 x 3 or 2 x 3, you have the option to use a wider spacing between the pocket holes.
If you are using a model 720, 720 Pro, or a 520, you could use the two drill guide holes to the left – the single hole and the left hole of the 2 holes spaced close together. If you are using the model 320, you’d simply insert the spacer between the two holes if there was room; but if there wasn’t, or the holes would be too close to the edge of the wood piece, you’d want to leave the spacer out.
When the wood pieces are even larger, say 1 x 4 or 2 x 4, each of these jig models will still offer the drill hole guidance required. In the use of models 720, 720Pro, and 520, you’d simply use the 2 drill guide holes farthest apart; and with the model 320, you’d leave the spacer in between the two drill guide holes.
Joining Large Work Pieces With Pocket Holes
What if the wood pieces are larger than those mentioned above? For instance, what if you are using plywood, panels or long pieces? Maybe you are making a tabletop and want to use pocket hole joinery to form it.
There are no jigs that take the thinking and calculations out of the joinery process for you, but it’s still joinery easily done.
Along the span of the plywood, panel, or long piece, you’d want to start 2” from the end of the workpiece and then space out additional pocket holes every 6” to 8” apart, ending 2” from the other end. You’ll probably still want to use glue – belt and suspenders – to supplement the strength of the pocket hole joint and then clamp until the glue has dried.
If we have not been clear enough in our descriptions, Kreg can help make it even clearer with their videos about the Model 720 and 720Pro in this first video:
And then their video about the Model 520:
And finally, the Model 320 with spacer:
These jigs almost take the thinking out of the process for you, with only minor choices to be made when working with smaller workpieces in your joinery. Even for the larger pieces, it’s not onerous – 2” in from the ends, and then every 6” – 8” along the span.
Pocket hole joints are easy, quick, and strong, and you’ll find many uses for them in your projects, just as we have at Obsessed Woodworking.