Modified heat treatment for 01 monos for 2016
As you know 01 is a favourite of mine for material in damascus and for my mono steel line. In past testing I have found 61/62 to be about the limit of edge stability. By this I mean primarily that it will form a fine edge in the first place and then take reasonable flex to either chip or distort it. In the case of 01 at 61 hrc with my current HT it is on the tough side, will take a great deal of flex, ultimately pushed to destruction it can make a small chip which shows a little distortion at the edges.
As quenched my 01 comes out at 66hrc then usually tempered back to 61hrc for stability. This is still considered a very nice place for this steel to be, great toughness and reasonable hardness.
However I often felt if I could get a little more hardness I could get a very stable fine edge which would chip clean with no distortion when pushed to destruction and with the added edge holding from extra hardness.
Long story short I tried a different HT technique which has given me success in other steels hoping to get more of the alloy carbides as well as carbon into solution and more evenly dispersed to gain edge stable hardness. Tested hardness for this test piece then was 64.5hrc average, with 3 spot testings across 5 points along the blade.
Test figures were the same average across the 5 points on the blade.
As we are dealing with considerable hardness on a mono blade I torched the tang and into the spine back to 58hrc.
Quick compound wide bevel grind and brome stick handle so I can find out if it is edge stable or not before anything else.
Finished the edge and final thin on the stones thin enough to flex easily with my nail, then tested the edge flex. The flex and return was very impressive, eventually with force I managed to chip it with a plastic pen. It chipped small, clean, no distortion and would not chip easily. This is a very very good start.
So to cooking a massive pasta sauce to freeze , been making my own pasta recently and enjoying it immensely
Also rather clumsily sliced 2mm off the end of my thumb! But was impressed how nicely dissected the piece was
I had mirror stropped the edge/over stopping, super fine/sharp but typically very quick to loose that initial uber sharpness for falling though tomato etc....Its the mark of a very fine carbide steel however and the best working solution is to strop test the edge then add some teeth back to the edge on a 6k or so stone. In this case I over polished the edge to see if it would stick in the tomato skin after all the dicing and board bashing. Not terribly scientific but knowing 01 so well in character It is a good quick test for me.
Tomatoes last of all, really squishy tough skinned on the turn ones, no issues with push cut.
So its 01, but not as we know it Jim, good bit harder!
Only downside is the HT has around 5 more steps, but by working in batches I think I can minimise time/price increase. I also have one more idea to try to achieve the same in less steps/more time. I will try and compare on the second test piece.
But will work with this piece for a few weeks until I have confidence no unexpected chips appear during kitchen duties...and if they do if the edge stabilises after a few sharpenings. Early testing shows no such issues however and great promise that this can be used for future 01 carbon Mono bringing hardness figures in line with my san mai/1.2442 and my double high carbon damascus.
So this will explain the published boost in hardness figures on 01 monos.
Great and informative read (almost makes me think my response should be longer haha)
Love how you continually strive to improve on your blades! Really excited for what you have in-store!
Nice job on the thumb repair Will. Any plans on wide bevel knives in the future or was that just for testing purposes?
How much for the test gyuto? this may be my one chance to own a catcheside!
Ha ha, thanks all, yes its just a quick rough tester, not for resale at the mo I need it for testing, though it may get tidied up later in the year and sold as an odd ball or something. Thanks though I'm going to try and do something as a group buy this year, meaning 10 or so people sign up for exactly the same knife so I can do them in a batch and something affordable, wide bevel is one possibility have a few other ideas too though, but will save that for later, have lots to get on with for the time being.
Originally Posted by WillC
Been eyeing/thinking about a Catcheside. The groupbuy just might put me over the finish line! =p
Originally Posted by WillC