The tails and pins interlock to form a strong 90-degree joint. Dovetail joints are technically complex and are often used to create drawer boxes for furniture. Through mortise and tenon – To form this joint, a round or square hole (called a mortise) is cut through the side of one piece of wood.The end of the other piece of wood is cut to have a projection (the tenon) that matches the mortise.The tenon is placed into the mortise, projecting out from the other side of the wood. A wedge is hammered into a hole in the tenon. The wedge keeps the tenon from sliding out of the mortise.he end of the other piece of wood is cut to have a projection (the tenon) that matches the mortise. The tenon is placed into the mortise, projecting out from the other side of the wood. A wedge is hammered into a hole in the tenon. The wedge keeps the tenon from sliding out of the mortise.