Thursday, March 23, 2017

Tools for making round tenons and such ...

Unlike a flat tenon, a round tenon does not resist twisting very much, but it is quite often used in chairmaking and can be made very strong indeed... without any glue even...

But we are getting ahead of ourselves.
Let's have a quick look at some of the tooling involved for making these connections.

There are many ways to make round tenons without using a lathe, here are some of the ones I used. Some makes a square shoulder, some a tapered or round one.

The first one is called an hollow auger, it goes around the square piece which was previously tapered by using a spoke pointer bit.
That first step, the tapering at the end, is crucial for the proper operation of the hollow auger. If you ever tried to used one of these without first using the spoke pointer you probably experiences dismal results... It would had been frustrating at best.

Such hollow augers were very popular at one time mid 1800s to early 1900 since they were crucial for the wheel wright in order to make quickly a bunch of same size parts.
Here is a video of making a wheel, notice the square, often tapered, tenon for the hub and the round tenon on the end of the spokes connecting to the felloes.

The outer part of the wheel, the Felloes, are connected by at least two spokes, terminated by a round tenon with a square shoulder, for maximum strength.

Being popular there were at least 85 different variations patented between the appearance of the first one in 1829 to the last American patent in dec 1911.
The advent of the metal wheels after WWI spelled the end for these hollow augers, after 1940 they all but disappears from tools catalogs
They were also used by chairmakers, ladder maker and yes some cabinet makers.

The spoke pointer on the left is the first tool to use before 
the hollow auger on the right. Note the often missing depth stop on the hollow auger, the red clip part

The one I used is a patented design from 1870 (then re-issued in 1877), called the C.S. Bonney pattern. As you can see, it is very close to the original patent.
It featured a rotating turret with 8 sizes holes, cutting a round tenon of the following sizes:
3/8, 7/16, 1/2, 9/16, 5/8, 3/4, 7/8 and 1 inch.

Original patent of 1870 No 105,896

Re-issued as RE7,689 in 1877

It is hard to read but mine has raised casting marks that read 
EC Stearns 260 (?) Syracuse NY

Red part is the depth stop, often MIA

The cutter is adjustable in and out (one screw on top), up and down (two screws at the bottom) and sideways by one screw bearing on one side (the long one in the last pic)

Took me awhile to find a decent spoke pointer, since then I came across a few... So I now have 3, two antique and a new one from Lee Valley.  Overkill? Well between these three I can handle various sizes... But honestly, you could get by with only one, it is just that they keep showing up since I started looking for them and they followed me home... Honest :-)

From L-R
2-1/2 in, 2 in and 1-1/2 in spoke pointers

So why must we use the spoke pointer before the hollow auger?
Well, the hole's sizes on the auger goes from 3/8 to 1 inch. These are the final sizes of the round tenon, but in all cases, the actual work piece, be it a wheel spoke or a chair part would be bigger than the actual tenon, in order to cut a square shoulder around it. How are we going to feed a 2 in piece into a 1 inch hole?? Simple, shave the end of the workpiece in a taper fashion (much like a regular pencil sharpener works) until the top diameter has been reduced to the required size to sit inside the guide hole on the tenoner.
That is why there is a depth stop provision (sometimes missing) on the Spoke pointers. It ensure quick correctly sized parts.

On this model, the stem of the tool is loose and can be adjusted in or out of the tool body. There is a set screw to hold the setting and a handy scale to help you guesstimate the setting 

That is the stem poking out in the middle of the tool

This model has a fixed stem but the wing nut set a small metal dowel rod in or out. Essentially same operation as above but no scale and being a separate piece, often missing. Look for it in the center inside.

In addition, if you were careful when using the spoke pointer, the reduced size part should be smack in the middle of the workpiece. This will then help centering the round tenon to be cut on the workpiece.

Sound good in theory, it is so easy to introduce small variations by tilting the tools in use. Remember we are using a hand brace to turn these tools.
I don't have much experiences with them, but I found it very easy to get the tenon started with a small offset.... As usual your actual results may vary... :-)

Next up to bat are these Veritas Dowel and Tenon makers and Tapered Tenon cutters .

From what I understand, they are basically the same castings, the difference being simply the blade that come with them.
I got the set of three Tapered tenon cutter which uses a straight across blade (think pencil sharpener on Viagra :-) and the dowel makers used a curved blade which can be interchanged in both to transformed the tool into one form or the other. So I bought a spare curved blade to try it out.

They work the same as the previous spoke pointers except that the cutting geometry is changed, they either produce a flat continuous dowel or make a shallow taper on the tenon. Such tapered tenons being used mostly in chairmaking.

And our last tool in this line up is a Stanley No 22, 3/4 in dowel pointer

Another simple pointer tool, work the same as the previous ones, with one notable difference.
The blade (cutting edge) is not removable, being cut into body of the tool. You have to be very careful when attempting to sharpen it. You can easily ended up with a very shiny cutting edge (Ralph Tm :-) which would not engage the workpiece. Essentially ruining the tool... just saying...

The good news is that it does not have to be super sharp to work...

Such a tool would have come handy in the days prior to the availability of properly shaped dowels available at your local hardware stores. If you make your own dowels, using such a tool would quickly put a small taper on the ends.

Bob, turning around and around and...


  1. Very interesting as usual, Bob. I think Veritas sold lots of the tapered tenon cutters after Schwarz wrote about "stick furniture".

  2. Bob,
    I can't imagine using them in a hand brace - 2 1/2" diameter. And that multi hole one looks like it weighs a ton. That must be a joy to turn with all that excess metal off center from the hole you are working on.
    Do the LV ones use hand or electrical drill power? Or both?

  3. Ha Ha they are not that big nor heavy, even if made of cast iron.
    The Veritas ones are designed for hand uses. The dowel maker can uses a small square socket to drive the piece of wood with a drill, but it does caution about overheating in the instruction. Steady and slow win the race...

    Bob, slowly making his way back up from the mountain of info I got on the No 120...

  4. Hi Matt
    Thanks for your comments, I try :-)
    Correcto, I am sure the schwarz effect made its impression on their sales :-)

    Bob, getting slightly better. God I hate Man cold!

  5. Hi Robert,

    I picked up a Stearns hollow auger a while back,but have no idea how to set the iron. I did hone a 30* bevel on it, but have no idea how much should be poking into the " corner" of the desired hole.

    I was fooling around with common 2 x4 trying to get a 3/4" round tennon, but I think a beaver would have left cleaner toothmarks.

    So just how much iron should be poking out?


    Edward in Vancouver

  6. Hi Edward
    Yes, there are a few adjustments on it;in/out, up/down, each corner independently and then laterally.
    I will admit it is a tad tricky to set :-) I was going to include a how to in this post but i need to clean up my shop in order to access my bench. My days of using the kitchen table are over i'm afraid :-)
    It would be a lot easier to explain visually than in words, so hang in there it will be forthcoming...promise
    Meanwhile, if you do not have a proper spoke pointer, get one. LV has the red one shown in this post in clearances right now, I just bought it :-)

    Bob, who has tools stashed everywhere and need badly to do something about them...

  7. Thanks! I do have a pointer--Stearns as well. Gave the blade a new bevel and a 30* microbevel, and it cuts like a pencil sharpener!

    I have fidled and farted with the hollow auger, but I am pretty sure I have too much of the iron poking out. And changing tenon sizes means more fidling with the iron all over again.

    I picked up the hollow auger in order to build cedar " dog cages" to fit around our fruit trees. I ripped the cedar into 2x2's and built the square cage with 3/4" holes and tenons. In the end I hand cut 3/4" square tenons and shaped them with a chisel. Once I banged them into the round mortises and wedged them, they looked pretty good.

    Still, I'd like to learn the "mysteries" of this tool and use it for its intended purpose......

  8. Thanks Bob,

    As always I learn something reading your posts.