Woodworking often requires connecting pieces of wood together; the connection is referred to as a joint. There are many types of woodworking joints. Which joint to incorporate in the construction of the piece is often dictated by function, as well as skill of the woodworker. In this article, we highlight five woodworking joint types, their uses, pros and cons.
Five Woodworking Joint Types to Consider
- Butt Joint
- Pocket Joint –screws or dowels
- Miter Joint
- Mortis and Tenon Joint
- Box Joint
Before You Start
While each joint may look different, have different strength or characteristics, to create a satisfactory joint requires following some basic woodworking fundamentals and using proper tools. Of course, access to a fully-equipped woodworking shop is ideal. However, even with minimal tools and space, you can create functional pieces with solid joints. Here are some basics to consider.
Arguably, the single most important factor to consider in creating a satisfactory joint in woodworking is to have square, clean edges and surfaces to connect. Not only will the joint look better—clean and precise—but it will function better as well. So, how to get those clean, square edges?
First, take great care in measuring and marking. Precise measuring is often a function of tool choice and taking time. There is a reason for the adage “measure twice; cut once”. Take your time. Use the highest quality tools you have access to. A carpenter’s square needs to be square. A pencil needs to be sharp. Measurements need to be accurate.
Some tools to help you achieve precision with measuring and marking are: a mini-square, caliper, bevel gauge, sharp pencil or awl.
Once you have transferred the line to wood and are ready to make the cuts, use the sharpest tool available and one which is designed for the use. Band saws are often ideal for practical joint work, however using hand tools like a fine-tooth crosscut saw, or Japanese hand saw can work just as well. Sharp chisels and a mallet are indispensable for cleaning up surfaces and edges. Again, access to a full shop with a planer, joiner, table saw, miter box, band saw, miter box and a wide assortment of clamps would be ideal and would help you create the precision a good joint requires.
You’ve transferred the measurements, made the cuts and you’re ready to fasten the pieces together. First, place the pieces together in the joint and make sure they fit together as planned. A good joint is snug, with all surfaces maintaining contact; there should be minimal space between the connected pieces of wood. When you have ascertained the joint meets these requirements, now’s the time to fasten the pieces together.
Whether you apply wood glue or no glue, using a fastener like a screw, dowel, nail, or wood pin is entirely up to you, however, consider the type of joint and the end use of the piece when choosing the fastener. As an example, a joint on a picture frame will have to withstand less force than a table leg and as such will require a different method of fastening. Both use joints, but to very different end use. A word of caution: when using a permanent fastener—like glue—it’s a good idea to make a dry run of placing all the pieces of your project together before applying the glue. Once the glue sets, if you’ve created a good solid joint, it will be difficult—if not impossible—to “unglue” the piece without destroying your work. Make sure your joints work well before gluing them together.
Finally, one more woodworking adage is appropriate: “too many clamps are not enough”. Often, a good joint requires glue and adequate set time to guarantee it meets the functional requirements of the piece. Access to a wide variety of clamps—sizes, types, shapes, styles—will go a long way to helping you achieve woodworking joint mastery.
Five Woodworking Joints – From Basic To Advanced
The following five woodworking joints will provide you with a starting point in your woodworking joint practice. Each joint will be described, its pros and cons listed, when to use and which can be accomplished by beginners and which should be reserved for more intermediate to highly skilled woodworkers.
The simplest joint in woodworking to attach two pieces of wood together is the Butt Joint, called so because the joint is created by “butting” two pieces of wood together. Imagine picking up two blocks of wood and placing flat surfaces together. Voila. The Butt Joint. But, hold on. How many ways can you place two surfaces together? End grain to end grain. Long grain to end grain. Long grain to long grain. For a ninety-degree connection, typically the joint runs end grain butted against long grain.
This joint is particularly well-suited for the beginning woodworker, insofar as it requires minimal tools and skill. Measure, draw accurate lines, cut and fasten, typically with glue and finish nails or screws, depending on end use. An example of a project using a butt joint could be building a box for a garden raised bed, interior window frame or the sides of a simple box. Tools needed: square, pencil, saw, fasteners.
Pros – the simplicity of this joint makes it particularly attractive and accessible for many applications and for those who don’t have access to a well-equipped shop or tools. The key is to make sure the cuts and surfaces are straight, flat, clean. Butt joints can be made quickly.
Cons – though simplest the Butt Joint has the potential to be the weakest joint. Unlike other joints that capitalize on the inherent qualities of the wood itself, the strength of the joint is entirely dependent on the means of how you fasten the wood pieces together. Consider carefully the end use of the project when choosing a fastener. For example, even a good wood glue will not create a strong butt joint in and of itself. To strengthen a butt joint it’s recommended to use both glue and another type of fastener, say nails, box, finish or corrugated (wiggle), screws, pins or dowels. Of course, which fastener to use is often dependent on the thickness of the wood. The strength of the butt joint will increase considerably with the additional fasteners; glue alone is not recommended in all but the simplest cases that will not require a strong joint.
Pocket Joint –Screws or Dowels
A Pocket Joint is essentially a Butt Joint with the added component of screws or dowels inserted at a specific angle through pre-drilled holes. A recommended angle of 15 degrees from the surface of the wood for the pilot hole is considered standard. Place the two pieces together at a right angle as in a Butt Joint and drill from the inside surface of the end-grain piece into the face of the long grain.
Tools needed: square, pencil, saw, drill and bit, a means of clamping the pieces together while drilling, fasteners – screws or dowels; optional though highly recommended—Pocket Jig. This would be a good next joint for the beginning woodworker and a practical joint for the advanced woodworker looking for a quick, functional joint.
Pros – this is a glorified Butt Joint, but much stronger and less prone to falling apart. By pre-drilling the holes through the end-grain piece of wood into the long-grain of the piece to be attached, a stronger joint is accomplished. Creating a Pocket Joint is fast, like the Butt Joint. Unlike other joints that need drilling, a Pocket Joint requires drilling only one hole and so does not need as accurate an alignment of pieces prior to attaching. Glue is not essential, though depends on end use.
Cons—depending on use, this joint can work free over time if not glued. Look at how the legs of your dining room table or chairs are assembled. Often, it’s through use of a Pocket Joint. Another con may be if you don’t have access to a Pocket Joint jig it may require some time to align the pieces and hold them in place secure enough to drill accurately.
Think of the corners on a picture frame. Got it? The pieces meet in the corner, each cut at a forty-five-degree angle. The Miter Joint is a practical woodworking joint especially suited for picture frames and box sides. Though cutting a forty-five-degree angle can be accomplished without using a Miter Box, the success of your cuts will be enhanced with some type of guide to keep your cut at the perfect angle.
There are two main things to consider when cutting for the Miter Joint. First, make sure you have measured the distance required for your cut to fit perfectly. Typically, measuring the longest side to longest side along the board will produce the best results…inside measurements can be prone to inaccuracy. The second aspect to consider is to take good care with your cut. A mitered cut is not as forgiving as some and can throw off your angle resulting in a frame or box that does not fit together, no matter how hard you try.
Along with the required tools listed above for the other joints, a miter box, or simple forty-five-degree jig would be helpful. Clamping the wood in place before cutting is also a good idea.
Pros—the Miter Joint, when done correctly, creates a clean, crisp edge along the end-grain of the pieces you are connecting. Though, unlike just butting two pieces together, the angled cut makes for a larger surface area for gluing, and it’s end grain on end-grain. This can translate to a stronger joint. As with other joints, adding a dowel, screws or nails can enhance the strength of the joint, if aesthetics is less of a concern. For picture frames and other projects where a side is not exposed, use of corrugated nails will strengthen the joint.
Cons—getting the measurements and the cuts just right can be challenging and takes practice. One of four mitered joints may be off and as a result the entire project suffers. You would do well to invest in some form of forty-five-degree jig and clamping system. More than others a mitered project would benefit from making sure all joints are perfect, pre-assembly.
The Miter Joint is a “must have” in the woodworker’s toolbox. While not a good option for a true beginner, it should be on the list to attempt after feeling comfortable around the shop.
Mortise and Tenon
The Mortise and Tenon is one of the oldest, tried and true woodworking joints in use, and for good reason. When well-constructed the Mortise and Tenon is strong, has multiple uses, is tolerant of slight inaccuracies in measuring and/or cutting. This joint can be hidden—giving the impression of a Butt Joint—or it can be visible with the Tenon protruding from the Mortise, adding a rustic or artistic flair to a project. Mortise and Tenon joints are used in everything from post and beam construction to small, heirloom furniture projects. This is a perfect joint for an intermediate woodworker to improve chops with.
The Mortise and Tenon gets its strength and beauty from cutting a hole or slit in one piece of wood–the Mortise–and cutting a finger or Tenon the exact dimension to fit inside the Mortise in the other. When done properly the tenon fits into the mortis snugly, maximizing surface area and the inherent strength of the wood. An exceptional Mortise and Tenon joint would require minimal glue—often the friction of the joint serves its purpose. That said, glue is the most common way to keep the joint secure.
The keys to making a satisfactory Mortise and Tenon joint is to measure and cut accurately. Tools to best help include some form of drill—drill press, bit and brace, hand drill—and chisel and mallet. The tenon can be cut with crosscut and rip saws if a bandsaw is not available. However, to clean the shoulders of the tenon and size the tenon itself, a sharp chisel is indispensable. Likewise, cleaning the sides of the mortise is best accomplished using a chisel.
Pros—the Mortise and Tenon is strong, relies on the inherent strength of the long grain of the wood. When done properly it’s hidden and requires no other fasteners, though glue makes the joint permanent. The joint is versatile, being suited for large or small projects.
Cons—taking care to get the shoulders of the tenon correct, as well as the depth of the mortise are often the biggest challenges. Though, to be clear, the latter is more a structural than visual problem. Skills with a chisel are required. Not a deal breaker and something a beginner should work toward.
The Box Joint is popular for its looks, function and ease of making—IF you have the proper tools. The joint is comprised of “pins” offset on each of the pieces to be joined at a right-angle corner. While it is possible to create the Box Joint with hand tools – fine toothed cross cut and a chisel—this joint is especially well-constructed using power tools such as a router with a jig, a table saw with a jig, even a band saw set up with stops. Think of the Box Joint as having the pins approximately the same dimension as the thickness of the wood, cut to fit opposite the piece it attaches to. This is an excellent joint in incorporate in boxes and fine furniture.
Tools required include the power tools mentioned above, some understanding of jigs and/or setting stops on the saw table. Once the jig is set up, it’s merely a matter of measuring and cutting with care. Before gluing—as with all joints—make sure the fit is snug. This joint optimizes surface area for gluing; often that is all the fastening that is needed. The alternative would be to add a tiny pin at either top or bottom of the joint.
Pros – this joint is attractive, strong and—with the proper tools and skills—easy to make. Being completely visible, the joint can add pop to a project, as well as function. The nature of the Box Joint makes it especially suitable for projects that benefit from a production-line approach.
Cons—the Box Joint depends on accurate cutting for ALL the pins…not just a few. If you decide to use the Box Joint, take care in setting up the jig and in the cutting process. If your first pin is off, the rest will most likely be off as well. This is not a joint for beginning woodworkers, suited more instead for intermediate to advanced.
Connecting two pieces of wood together with joints requires choosing a joint appropriate to the end use, attention to precise measuring and cutting, and use of proper tools. The five woodworking joints presented here represent an overview of the types of joints available and their difficulty. By beginning with the simplest Butt Joint, following care in measuring and cutting, and taking the time to master it and the other joints listed, the woodworker will be well on the way to creating projects that are functional, durable and pleasing to the eye.