Bill Kirkley

I have a Mankel forge. I like the clamshell designed. It is forced air. http://mankelforge.com/forges.html It is a nice forge. I have considered building one but buying one is a quick and easy way to get started.

I finished my second filing jig ( the horizontal one in the photo). The file skated before tempering. I tempered this one for a little over an hour at 350f twice. I clamped a piece of 1/4X1" flat bar tightly and the jig I didn't break. So it must not be brittle.

I used 1/4-20 button head screws to keep the pins from falling out.

Well guys I don't know! Unfortunately I did not test the jig with a file after it cooled down. After one 80 minute cycle at 400 a file did not skate across the edge with moderate pressure. With light pressure I guess it did. It definitely bit into an annealed bar more than the one I heat treated My anvil is advertised as a hardness of about 54. I tried the file on an edge and it didn't skate any more than on the "hardened" filing jig. So again I have no idea if the jig is hardened much. Each half of the jig was wrapped in paper then foil. They were placed in a room temperature Paragon fernace and heated to 1400 degrees at full ramping. They were held there for 30 minutes then heated to 1775 and held for 30 minutes. It took about 45 minutes to cool to the point I could grasp the pieces for a couple of seconds. At that point they were tempered once. The file does skate on the flat surface. But it does that on mild steel as well! So maybe it will work as is. I am going to do another one. Maybe the file will skate if I try it before tempering. The pins fit just as well as before the heat treat. The bolts also fit, but one was a bit snug.

Dan, I've never done brazing. I'll have to give it a try. I'd love to see your guide. Will you post a picture?

The carbide idea is interesting but I am going to heat treat for the experience. I may try J J's idea later.

J J, I have used carbide inserts on my lath and had one break from misuse. I think they may be brittle. If that's the case would they possibly crack if the steel flexed from tightening as Jerrod pointed out?

I don't know anything about carbide blanks. A 1/8x3/8x6 inch blank from usacarbide.com is about $11.00. The same size on mscdirect.com is about $57.00. Any idea why the discrepancy?

J J, that's an interesting idea! If I did that I don't think there would be a need to heat treat. Taking it a step further they could be made out of mild steel. I guess I would machine a slot so the carbide blanks would sit a little proud and epoxy them in place. Does that sound right.

Good point! I guess I'll temper it at 400 which in theory will be a hardness of 60.

Thanks guys. According to the chart I have tempering at 300 degrees gives a hardness of 62 and 400 degrees a hardness of 60. Do you think it would matter if it were a little brittle? There should be no impact. The only problem might be if I dropped it. I believe files are pretty brittle yet functional. My foil is supposed to arrive tomorrow so I will heat treat it Saturday. Thanks again for your help.

Thanks Jerrod. Below is the information I found for A2. It looks like tempering at 950 degrees gives the best toughness and good hardness. But what would be best for resisting the file, toughness or hardness?

Thanks Alan! It will be interested to see if the drill rod still has a good fit after the heat treat. I've never done something like this. Do you take it out of the foil to "quench"? I saw on YouTube where someone blasted the part with compressed air to "quench". Is that advisable or would it be too rapid a cool down?

I got a box of A2 at an auction. It included a 3/4X1 1/4 inch flat bar. I used it to make a tang filing jig I have seen on the net. I used 3/8 inch W1 drill rod for the pins. Now I need to heat treat the blocks. I found a recipe that called for stress relieving, preheat, and hardening. Do you keep the part in the same foil for each cycle? After hardening do you take it out of the foil to cool in "still air"? Should I set it on a brick or metal to cool? They describe putting wood in the foil. Would wrapping the part in paper do the same thing? Is there a need to heat treat the pins? Is there something I am overlooking? Thanks!

Thanks Jerrod! The wires are .105 inches in diameter. I did in fact toss them into a metal container after they were heated and bent. I guess the heated area of some hit the side of the container and were hardened, while others did not. I was at a loss to figure out why some were soft and some hard. Thanks again.