Woodworking Joints: How to Cut Dado Joints

What You'll Need
Wooden planks
Wooden file
Combination square

Dado joints are popular woodworking joints. A dado is a rectangle grove cut into a plank of wood and a dado joint is a working joint, done to join two planks of wood together with the help of adhesives, fasteners and bindings. The process of cutting is simple and can ensure immense strength in your project if done properly. Dado joints are usually needed for big projects like wooden houses and smaller projects like wooden puzzle toys. To learn how to cut dado joints, follow the steps below.

Step 1: Mark the Boundaries

Mark the wooden plank with two perpendicular lines that are slightly apart to mark the position and the width of the dado. Use a combination square to complete this step. The lines should form a 90-degree angle.

Step 2: Placing the Blades

The combination square blades must extend a distance that is equal to one half of the depth of the plank. For example, a plank that is ¾ inch deep would be 3/8 inch. The blade of the square must be kept against the corner of the plank to mark the foot of the dado. Place a mark on the edge of the dado with the help of a blade of square.

Step 3: Cutting

Saw four kerfs (incisions) in the dado. Ensure you stop the kerfs at the bottom of the dado. This can be done using a backsaw or a miter-saw. Use a chisel to remove all extra wood between the kerfs. Check the depth as it must be consistent and uniform.

Step 4: Smoothing

Use the flat wooden filer, to smooth the bottom of the dado joint.