Our latest methods are still in the experimental stage, waiting for the lab to report back.
The stuff we were doing when the test blade reported in Blade Magazine was worked up were as follows:
An old rhyme has guided me for years, even before I heard it from J D Smith.
"If thou wilst a keen edge win
forge it thick and grind it thin"
After the forging was complete, two blade smith normalizing heats:
heat to critical, confirmed by a magnet, hold blade in a shaddow, it will turn dark, then brighten, then reheat to critical again, be careful to keep the tip from over heating and cool the blade in a shaddow, watch the the colors change again. The blade will be magnetic at this point.
Full normalize heat, to critical, check with a magnet and allow to cool to room temp. in still air. Don't hurry it let it cool slowly.
Then three blade-smith anneals (that is what I call them). Heat to 800 degrees, hold for two hours and let them cool down slowly. (I do this in three days, 24 hours between heats, in the house hold freezer over night.
Many question the 24 hour cycles, I use them because I believe in them, steel takes time to enjoy where you want it to go, tincture of time has never hurt.
Grind the blade evenly, right side, left side.
Take the blade to a 220 grit finish. Any deeper scratchs can influence the grain structure below the scratch.
Texaco Type A quechant is the oil I use for 52100 and 5160. You can purchase some from Shane Justice. If you use any other oil we are not on the same page.
The specks call for heating the oil to 135 f. I speed my oil up just a little by heating it to 165 f. (I experimented with oil temps a lot to figure this out, you may need to experiment on your own to find what works best for your blades.)
Heat the blade to critical, catch it right at critical or a little above, if you allow it to cool, it will remain non magnetic but be too cool to harden. Use the magnet religously!
Quench the blade in the oil to the depth you wish to harden. When it quits fuming, fully submerge the blade in the oil and allow the oil and blade to come to room temp. Blades then go back to the home freezer overnight. I try to keep 24 hour cycles. repeat the quench cycle for a total of three quenches.
I then temper the blades, again three cycles 24 hours apart. I believe that more time between cycles would be of benefit, but remember we got to make a profit!
The first tempering temp is 330 f.
Grind off a little of the edge flat to get to the best edge possible, then grind the blade to its final edge.
I test this edge, edge flex, then cut. If the blade chips on the flex test, I temper higher. Depending upon the nature of the chips I may to as high as 10 degrees for the next three tempering heats. Then test for chip again, if it chips try a higher temper temp. if not, test for cut.
The nature of the blade dictates how you need to treat it. It leads you through, if you try to lead, she will let you down.
The above is the basics, we can go further if we chose.
If you have seen the Bowie in my advertisment in Blade with the close up of the tip over the blade, you will see a blade that was plushed to the limit, (at that time). Only four men who looked at her had any idea what she was. The methods used on her were based upon advice from a fine gentleman who I met years ago, He was in his late 80's, had forged steel since he was 14. He had just solved a problem for what was then a fledgling company. The men of science could not shape the tool, he figured it out in a few weeks.
I asked him how? He smiled and said "Thermal Cycles". Thermal cycles and time have kept me interested in the forged blade, I see no end in sight.
WE have an unlimited number of variables that can influence the nature of the blades you complete, pay attention to everything, keep notes and only one major rule, enjoy.
There are many who will take pot shots at you when you explore, do not let them discourage you. You must be your greatest critic, this is the satisfaction that remains.
I did not get to the above on my own, Bill Moran taught me the basics of forging in such manner that I had more qustions than answers, and still do. This is the mark of a great teacher. Wayne Goddard taught me a lot about testing. Rex, Doc. Bill Burke and I have been working this stuff out for years and we still have places to go.