It’s time to get serious.
I showed in the last two posts how easy it is to make small tenons on very small work pieces; in this case I have rails that are about 1 inch wide. With the small piece of furniture already designed, It is time to get down to business. First thing to do:
Optimize the tenon fit.
What do I mean by “optimize the tenon fit”?
We always want a tenon that fits in the mortise “just right”. This means the tenon:
- Is easily driven into the mortise.
- If you must use a mallet to drive the tenon, it is probably too “fat” for the mortise.
- Ideally, when you have the tenon all the way in the mortise, it should not “fall out” of the mortise. If it does, the fit is too loose.
- The tenon should be a several thousands of an inch shorter than the mortise is deep.
- Once you have the fit to your liking, remember to adjust the router bit such that the tenon is shorter than the depth of the mortise. If you forget to make the mortise a little deeper, make the tenons shorter. My choice to do this is almost always the miter box, followed very closely by my shooting board.
How I optimized the fit.
In two steps I had the fit within 0.001″ (one thousand of an inch!). See the photo on the right; the gnomon is made of 1-inch cubes.
Why did I do two more test tenons and mortises? Because I always confirm that the “perfect fit” I got was not a fluke when I hit the sweet spot. This spot is reached when the tenon thickness is only a few thousands of an inch thinner than the thickness of the mortise, and the tenon slides into the mortise easily without the tenon piece falling out easily.
The two additional tests required about 5 minutes to make. Now I am certain I can proceed with the machining of the joinery for this small project.
What do you do?
- Do you go to the same amount of work?
- Or are you good to go with the first test?
- And, following the first test, do you then use hand tools to reach the final fit?
I would love to hear from you. Thanks!



