A lock joint is a good drawer joint because it holds together tightly as the drawer is moved. Use a 1/4" dado stack for this project. Set the blade 1/4" above the table. Set the fence 1/4" from the blade edge. Place a board flat against the table top and tight against the fence.
Make a cut on all the way across the board. This board will be the drawer side. For the drawer front, cut a 1/4" x 1/4" rabbet. So that you don’t have to change the blade setup, Use a 1/4" spacer board between the fence and the board. Use your miter gauge to hold the board and maintain the spacing as you push through the cut. Change the blade height to 1/2".
Stand the drawer front vertically for the next cut. Make the cut through the end of the board, holding the board tight against the fence. Make sure to hold the board above the cut area and out of harm’s way. Put the two boards together to make a lock joint. Remember to use glue to bond the joint. To make a lock joint on a table saw using 3/4" material, follow the first few steps up until step 5, cutting the rabbet. For 3/4" material, use a 1/2" x 1/4" rabbet; don’t use the spacer to make that cut. Then, raise the blade to 3/4" to make the vertical cut.