Every woodworker must join pieces of stock together at some point or another. Even if you're already working as an apprentice or under the guidance of a pro, you may not know the names of the most popular joints you'll come across. Getting to know the different methods of joining wood and the strengths (and weaknesses) of those particular joints can further your journey to become an expert woodworker.
Butt Joints and Miter Joints
The butt joint is the simplest joint – it's named because one piece of wood stock butts up against another and is affixed using nails, screws and sometimes glue. These joints are the go-to for simple 90-degree angles that don't require being 100% precise or inherently strong. Butt joints are great for making frames, boxes or other square or rectangular projects that don't bear too much weight.
The miter joint is a close cousin of the butt joint – it's basically an angled butt joint. Each piece of stock is cut to a precise 45-degree angle. When glued together (nails are less commonly used), this joint produces a perfect 90-degree angle.
Biscuit Joints and Spline Joints
Biscuit joints and spline joints are reinforced versions of the simple butt joint. In a biscuit joint, you attach a biscuit – a circular piece of wood – in mortises on each piece of stock. Although the biscuit makes the butt joint stronger, the attachment of them makes the join imprecise. Thus, it's not ideal for finished work that will show. Think drawers and recessed fittings.
Spline joints are reinforced with a piece of plywood or other material inserted along matching grooves or plows in each piece of stock. The spline reinforces the join and is a viable substitute for the tongue and groove joint. These joints can also be used as decorative accents using contrasting wood.
Tongue and Groove Joints
Tongue and groove joints are popular in the woodworking world for large projects – making a tabletop out of multiple pieces of stock or laying wood flooring. A channel is cut on one edge of one piece of stock to form the groove. On the matching piece of stock to be joined edge-to-edge, a tongue is cut. The tongue and groove allow the joint to fit snugly together. If you're working on a piece or with materials that require you to factor in shrinkage, tongue and groove is the way to go.
Box Joints and Dovetail Joints
Box or finger joints are so named because they look like interlocking boxes or intertwined fingers. This popular joint creates a strong right angle and is commonly glued together. The edge forms a decorative join and is perfect for visible angles that require good structural integrity.
You might use a finger or box joint to make a jewelry box or other item where the edges can be seen.
A dovetail joint is a close cousin of the box joint, but it requires more precision and accuracy as the intertwining pieces of stock that are pushed together to form the right angle are also angled or serrated, rather than square. The dovetail joint has more strength than the box joint and is the preferred choice for attaching drawer sides to fronts.
Some of the most popular types of woodworking joints are also the simplest. Whether you've been making them for years or are a complete woodworking newbie looking to further your craft, knowing the most basic and common woodworking joints can help you on the job.