Butt joints are one of the simplest joints employed in woodworking, where the wood is joined using the ends, edges or faces by glue and/or other mechanical means. While these joints may be inherently weaker than other joints, they can be reinforced to provide reasonably strong joint that can compete in strength with mortise-and-tenon or dovetail joints. There are a wide variety of applications that can use butt joints.

There are essentially six types of butt joints: end-to-face, end-to-edge, edge-to-edge, face-to-face, end miter, and face miter joints.

End-To-Face and End-To-Edge Joints

The End-To-Face joint, also called a corner butt joint, joins the end of one board to the face of another. It is typically used in casework, shelves, and other simple assemblies where appearance is not important.

The End-To Edge joint, also called a frame butt joint, joins one edge of a board to the end of another. It is used primarily to join sides, top, and bottoms of casework when appearance is important.

These joints can be considered among the weakest of the butt joints. This is due to the nature of the grain of the wood and the minimal gluing surface available. The end of the wood is typically highly absorbent and therefore provides a poor gluing surface.

Edge-To-Edge Joints

This joint connects a board along its edges. They are used primarily for building the tops of tables, desks, and other wide surfaces using narrow stock. These joints are fairly strong due to the large surface area available for gluing and lack of end grain. Though these joints typically do not need reinforced, they can be using dowels, splines or biscuits.

Face-To-Face Joints

This type of joint requires joining two or more boards to make a thicker piece. These are commonly used for butcher block table tops, or to create a thicker piece, such as furniture legs, columns, and mantle pieces.

End Miter Joints

This is a type of beveled joint that joins that are in different planes together at an angle. These are used primarily to join the sides, tops, and bottoms of casework when appearance is important.

Face Miter Joints

The face miter joint is used primarily for picture and mirror frames, frame-and-panel construction, and face frames for casework. It joins the ends of two boards in the same plane at an angle so end grain does not show.

While only a brief description of each type of butt joint has been presented here, it shows the wide variety of applications for which they may be used. Some of these joints may be weaker than mortise-and-tenon or dovetail joints however, when reinforced with dowels, splines, biscuits, or glue blocks, they produce very strong and stable joints.