This article provides a quick run down on common woodworking joints that you may come across in implementing a set of bookcase plans, or any woodwork plan or project. There are many different types of joints which vary in complexity, however you'll often find that the more complex the joint is, the stronger it is. So here's the basic run down:
Butt - this is a simple joint which involves joining the two pieces of wood edge to edge. It is usually reinforced with glue and/or screws. Lap - this joint provides a modification on the butt joint which involves making a rabbet in the overlapping piece of wood. This adds to greater strength as there is more glueing area. Mitre - A mitre joint looks appealing but does require more accuracy in cutting the pieces. In a mitre joint the two pieces of wood are cut at 45 degrees and joined together to make a corner. Dado - This is where one piece of wood had a rabbet cut and receives the other piece into the rabbet. The dado joint is popular for bookcase shelves. Dowel - this is a straightforward yet strong joint. It requires holes to be drilled and dowels glued into place to hold the joint. Mortise and Tenon - this joint is a strong joint. It takes a bit more effort to master and involves cutting a hole in one piece of wood that will receive the other piece of wood. Tongue and Groove - this joint is often used for floors and paneling. It allows for the wood to move with changes in temperature and involves cutting a groove in one piece of wood and a tongue on the other piece that fits into the first piece of wood. Dovetail - the dovetail is an aesthetically appealing joint. It has an interlocking appearance. It is quite strong but requires patience and time to cut accurately.