There are many types of wood joints to choose from when building furniture. Naturally some are easier than others and which one you decide to use depends on a couple things:
What tools you own Your experience level Your comfort level with your tools Application of the joinery technique
Compound Miter Saw
Some of the most common types of wood joints are:
Butt joints Dadoes and grooves Dovetail joints Mortise and Tendon Pocket hole joinery Biscuit joints Miter joints
Butt Joints
A butt joint is the simplest joint to make because there is no machining to do besides cutting your boards to length. Just butt your joints together and either screw or nail them together. A butt joint may be the easiest joint to make, however it is also the weakest joint you can make.
Butt joints are used a lot in construction. When you build a wall, you just butt your boards to your top and bottom plate and nail them in place. Trim work also uses a lot of butt joints.
I typically don't use butt joints when building furniture because it is just as easy to reinforce any joint with a quick biscuit joint or a pocket hole. They can be used if you don't know how to do any other joinery techniques, but they will not last as long. I would recommend at least a pocket hole jig or a biscuit joiner.
Dadoes and Grooves
Dadoes and grooves are basically just a slot cut in wood to match the thickness of the wood to be inserted into the dado or groove. Dadoes run across the grain and grooves run with the grain. They are basically the same setup and the results are the same. If you were using 3/4 inch plywood and you wanted to make a cabinet, you would have 3/4 inch dadoes and grooves cut in the plywood for joining them together and they make alignment go much easier because there is nowhere for the plywood to go except into the dado or groove.
They are used primarily in case work like cabinets and entertainment centers. They help with alignment and strength of joint.
Dadoes and grooves can be made from a number of tools:
Dado blade in a table saw. A dado blade is multiple saw blades put together to make up whatever size is needed for your project. A router either mounted in a router table or you can clamp a straight edge to your work piece. A radial arm saw can be used also to make dadoes and grooves; however you are limited in the width that you can make.
Dovetail Joints
Dovetail joints are a classic type of wood joint. They can be made by hand or with a router and a dovetail jig. There are two parts to a dovetail joint and they are the pins and the tails. In my opinion, dovetail joints are by far the best looking joinery technique there is.
Through dovetails is when you can see the dovetail from two sides. They are traditionally cut by hand, however there are dovetail jigs that allow you to make them with a router.
Half blind dovetails are used mostly in making drawers. They are only seen from the side. They allow the drawer to be opened countless times without pulling the front loose from the sides.
Sliding dovetails are used in knock down furniture which means they can be taken apart and moved easily. Also they are used in bookcases for the shelves
Mortise and tenon
Mortise and tenons are one of the oldest and strongest wood joints there are. Mortise and tenons are made when you cut a slot into a piece of wood that matches a tenon on another piece of wood. When you make a mortise and tenon joint, always make the mortise first and then fit the tenon to the mortise. I usually cut the tenon a little oversized and then shave it down to get a snug fit.
The mortises can be cut a number of ways:
Hammer and chisel (old school) Mortising machine Drill press with a drill bit and then cleaned up with a chisel Drill press with a mortising attachment Plunge router with a straight bit
The tenons can be cut a number of ways also:
router table table saw with a single blade or a dado blade
I mostly use mortise and tenons when building tables. I use them to attach the aprons to the legs. There are endless ways in which you could use mortise and tenon joints.
Pocket hole joinery
Pocket hole joinery is when you use a stepped back drill bit to cut a slot at an angle in a piece of wood to accept a pocket hole screw. You must use a pocket hole jig clamped to the wood where you would like your pocket hole. Pocket holes are made very fast and are a very strong joint. I use them for a lot of applications and mostly use them when making face frames for cabinets. They can be put almost anywhere and in my opinion should be used in every shop. You can buy a kit with everything you need and Kreg is the industry standard for pocket holes.
Biscuit joinery
Biscuit joinery is when you cut a slot in a piece of wood with a biscuit joiner and insert a biscuit into the slot and clamp the two pieces of wood together. When the biscuit soaks up the glue, it swells up and makes an incredibly strong joint. You will need a biscuit joiner to make biscuit joints. Biscuit are great for reinforcing miter joints. I use biscuits for attaching face frames to cabinets. They work great and there are no fasteners to be seen which the sign of a good woodworker is.
There are three sizes of biscuits:
# 0 (small) # 10 (medium) #20 (large)
The # 20 biscuit is the most common one used. The smaller two are used when the wood is small or thin. The slot size that is cut is the same for all three sizes, only the depth of the slot is changed.
Miter joints
Miter joints are made when you cut a 45 degree angle on two pieces of wood and join them together. They are used primarily on trim work for furniture and house trim. They can be made with a miter saw and can also be made on a table saw. Miter joints can be reinforced with a biscuit joint. There are also compound miter joints where the blade is also tipped to make the cut. These are used when installing crown molding.
I hope this article helps you with understanding the different types of wood joints and how they are used.
The Most Common Types Of Wood Joints Used In Building Furniture
