The legs for the workbench have different dimensions primarily because I was making the most of my reclaimed lumber purchase. The front legs are 7.5 inches wide and the rear ones are 5 inches wide. Both sets are 3.5 inches deep – perfect for holdfasts.
I decided on a double through tenon/dovetail with a plan to wedge the tenon in the bench top. The dovetail and tenon will each be 1 inch thick with a 1 inch gap between them. The remaining depth will be a shoulder behind the tenon.
Marking the lines with a marking gauge was straight forward, and I allowed for the tenon to be 1/8″ thicker than the top so it can be planed flush to the top at the end. The dovetail angle is 30 degrees. It looks good.
Sawing the tenons was long and hard work! My Ryoba is on its last legs so I finished most cuts with the recently acquired Disston ripsaw. I then tried to drill out the waste with a bit and brace like in this post by Will Myers (part of another awesome Roubo series) but it was hard work. This might be because the bit is not sharp enough (though I have sharpened it…) but in the case of the front legs there is 7.5″ to drill through! For the other legs I went back to a mortise chisel and the job was done quickly. I made a video to show just how quick this chiseling can be…