One man Tenon Spring Swage

unkle spike · January 2, 2009

I built this over the course of 2 days. The blocks are 3/4" leaf spring that I had to anneal before drilling. I heated to non-magnetic and dumped them in a bucket of Barn Lime, and let them cool over night.. I tried to drill them first and smoked a drillbit trying to get a starter hole, after anneal they drilled like butter. They cut fine on my HF tip down bandsaw, but drilling was another story.

I used one of the existing holes in the spring, slightly rounded a pin to fit that hole, and welded it to the bottom piece. While I had it clamped up I added the side guides. I then drilled a 3/8" hole dead center partway through and fit it with a spring that pops the two back up after you hit it.

I added a shaft at 45 degrees in the base to fit the hardy hole on my anvil. I figured at 45 degrees to the anvil I would have a comfortable working angle.

After I was done with all the drilling and welding, I re-hardened them by heating to non-magnetic again and quenching in water.

Now out to the shop to make a monkey tool....

Then I can try the combination of the two.

keykeeper · January 2, 2009

Right nice job you did there, Spike. Let us know how it works for ya!

jimbob · January 2, 2009

you might want to take the sharp edges off

unkle spike · January 2, 2009

you might want to take the sharp edges off

I did, I didn't want to grind too much off before I used it, I had to relieve the edges of the holes more, and some on the face.

It works well, now I need to get my monkey tool done.

HWooldridge · January 2, 2009

you might want to take the sharp edges off

Jim Bob is correct as a swage should be designed not to pinch the parent stock since the work is done primarily with about 30 % of the top and bottom surfaces. This means most of the corners are removed so the opening will be egg shaped as viewed from the front. If this edge break is not performed there will be fins coming out the side unless the forged stock is already very close to the finished size (less than 1/16 and even then there will be some pinch due to expansion from heat). The work is then rotated to round up the stock and every hit squeezes the material both lengthwise and sideways.

The monkey tool should also receive a radius on the leading edge of the hole so no sharp corners are introduced to the finished shoulder.

jwmotley · January 3, 2009

Nice job Jeff, be sure to show pics of your monkey tool as well. I still need to make some monkey tools myself.

unkle spike · January 10, 2009

Used the spring swage today, to make some tenons, first I had to make a set of necking blades for the guillotene. I had to have more room to the edge of the anvil or I would beat the shoulders up and couldn't get them squared well.
I also found you had to do alot of turning and tapping to get a good square shoulder, and keep it square for a good tight fit.

The first thing I found as pointed out earlier in the thread was I needed to radius the edges ALOT more than I had to keep from forming "wings" as I rounded them out.

The monkey tools came out of round stock, drilled 2 drill bit sizes larger than the tenon size.

I didn't take pics of using the swage, it works like shown, but necking a finished Tenon ready for clean up and hammering. I used a piece of 1 inch square stock to "seat" the tenon joint. I lightly hammered the end to start the swell for the head, hammered it down tight with the square stock and finished the head, this took 2 heats in some cases. Would be easier with a Oxy torch, but I don't have one. So I just put the whole piece in the forge for re-heats.

I did 3 different head finishes, cross peen, flat, and ball peen.