Mortise and tenon joinery has long been considered a hallmark of craftsmanship in solid wood construction, so there are lots of jigs, fixtures and machine setups out there that try to make it fast, precise and easy. The latest entry in that field is the E Z Pro Mortise & Tenon Jig (Model #870) from General Tools & Instruments. We decided to put it to the test.
What it is
The General jig is based on a sturdy aluminum extrusion and is designed to cut both the mortise and matching tenon at the same time using a standard plunge router with a spiral upcut bit. A ¼-inch bit is included in the kit, which works for ¼-inch thick mortises and tenons, but you can also cut 3/8-inch and ½-inch mortises and tenons with the appropriate bits.
Besides the bit and jig, included in the kit are bushings to fit common router baseplates, a bushing wrench and a centering tool to help in aligning your router base with the collet of your router, an Allen wrench for adjusting the jig, and a centering tool to make those jig adjustments easier.
How it works
The jig will handle stock from ½-inch to 1-1/2-inch thick and will make mortises from 1 to 3 inches wide. It is clearly designed to emphasize face-frame and style-and-rail joinery. I was going to use it for a table apron, but the legs I was using were larger than 1-1/2 inches, so that was a no-go. But for typical face-frame joints it excels.
To make your joints, you first mark center lines for both the mortise and the tenon on your stock. Then set the jig to the correct sizes and clamp your workpieces in place. Moveable alignment bars help you position the pieces and must be moved out of the way before cutting. I would have liked to have seen something to better square up the stock before clamping, but I used a T-square for this, which worked just fine.
Fast, precise joints
Cutting the joints is straightforward with a plunge router. I cut the tenons in three steps using the turret stops on my plunge router for depth of cut. For the mortise, I followed the instructions that came with the jig and an online video that suggested plunge drilling overlapping full-depth holes before moving the router back and forth to clean out the mortise.
Once removed from the jig, there is a bit of flange to remove from the tenon piece, but once you do that, the parts fit together perfectly.
This is a sturdy and reliable setup that could be semi-permanently mounted to a bench for regular use. At a retail price of about $150 it’s worth checking out if you regularly do this kind of joinery. For more information visit www.generaltools.com.
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