Lock Rabbet Drawer Joinery
Here's a router-made drawer joint that's quick, simple and self-aligning.
by Randy Johnson
For fast, easy, accurate joinery in everything from kitchen-cabinet drawers to jewelry boxes, the lock rabbet is the way to go. Lock rabbets are self-aligning and sufficiently strong for light- and medium-duty drawers. As with most woodworking techniques, there is more than one way to make a lock rabbet. We experimented with several methods using the tablesaw and router table and settled on this as our favorite. It uses a router bit called a drawer lock bit. And for the wood, we chose 1/2-in. Baltic birch plywood. Its multiple layers and lack of internal voids make it strong and stable.
Router Bit Setup
Setting up the drawer lock bit is not difficult. Start by aligning this bit with the fence, as shown in Photo 1. Next, adjust the height of the bit to approximately 3/8 in. (Photo 2). Run a couple of test boards (Photo 3) and check the fit (Photo 4). The first test boards you make are unlikely to give you a perfect fit, so adjust the bit's height until the fit is just right.
Marking the Drawer Sides
To determine the length of your drawer sides, subtract two times the thickness of the lip on your test board (Photo 4) from your final drawer box length. For example, if you're making a 12-in.-long drawer box and the lip on the test board is 1/16 in., the material for the drawer sides should be 11-7/8-in. long. Here's the math:
1/16" x 2 = 1/8"
12" - 1/8" = 11-7/8"
Prepare your plywood by cutting it into panels that equal the length you calculated with the formula above and are two to three drawer-sides wide (Photo 9). Add 1 in. to the width to allow for saw kerfs and edge waste. The edge waste will accommodate the chip-out that usually occurs when the router bit exits the cut. To rout the joint for drawer sides, hold the panel vertically against the fence (Photo 6).
Making the Drawer Box Fronts and Backs
Reset your router-table fence before you rout the fronts and backs. Set a scrap piece of your drawer-box material on top of the bit and move the fence back until the cutting depth matches the thickness of the material (Photo 7). Run a test cut with a scrap of drawer-box material and check the fit with the drawer side panels you cut earlier. It should look like the joint in (Photo 5). If the lip doesn't flush up with the side panel, readjust the router-table fence and run another test cut until the lip is flush with the side.
The drawer fronts and backs should be as long as the final width of the drawer box because they span the full width (Photo 5). These front and back panels are routed flat on the table (Photo 8)
Final Sizing
Now you can saw the drawer parts to final width (Photo 9). Then, saw or rout a 3/16-in.-deep dado in the parts for the drawer bottoms.
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