Date Tuesday, 21 June 2022, at 11:20 a.m.
I don't post on here, and that's not going to change. but I figured I would address the comments about hardness as there's some reality that would be more helpful than the guesses posted about hard tempered steel or scraping.
I don't temper these chisels hard. the steel itself has high hardness out of the quench. When you temper it, it retains a lot of that. At 64 hardness, it has higher toughness than anything offered commercially aside maybe from some high speed steels, but that's based on my results - as provided by Larrin Thomas (actual testing of hardness and toughness, not supposition).
I averaged toughness results just under 12 ft-lbs at an average hardness of 63.8. Same guy testing as the one who made the chart above, same testing equipment, same steel. Individually heat treating samples (not as a batch), I had hardness disparity in total of about 0.6 c scale points, nothing outside of 0.3 points from the mean. O1 samples were closer together in general (3 of 4 within 0.1 point on the c scale - by eye - separately cycled and quenched). O1 is more hardenable and was designed to be to through hardening, so the fact that it's easier to get less variance isn't a surprise. The idea that you can't judge the color of steel by eye in a constant light environment and harden it accurately is a myth, though - the results are not just out of the quench, but also include any variance that may have occurred when tempering - all were tempered in a toaster oven in a metal stack at the same time. You can literally do it just sitting on a floor with very little equipment.
I only got superior (to commercial) results with 26c3 - 1095 and O1 samples have about the same balance of hardness and toughness as commercial results. The reason for that is probably due to the high carbon content - excess carbon doesn't do good things in a long duration soak - it lowers the toughness of the steel. Attempts at soaking steel and eye temperature are probably possible with experimentation, but pointless and unlikely to be as consistent and the method that I use.
26c3 is available at retail, isn't horribly expensive, and doesn't need to be heat treated in a vacuum or soaked to get good results. that means anyone else could do this with propane, good indirect light - a garage during daytime away from direct outdoor light is good - and a toaster oven with a stack of metal to stabilize overall average temperature will be as accurate as most high cost tempering solutions (more accurate than a kitchen oven rack by a long shot).
For these to be chippy like V11 is at the top of its range or like hock O1 is until some of the edge wears off, it would have to be at the upper range of japanese chisel hardness - 65/66. I don't make chisels at that hardness level - they don't fare as well in work.
Is there a practical reason for a garage maker to use something more common or hire out heat treatment just to make a chisel less good? I don't know what it would be. 26c3 isn't for a beginner, but it's by no means that difficult to deal with once you understand that you give the steel what it wants and don't try to be a cowboy over-forging it (and overheating or decarbing it) or getting too cute with temperatures and underhardening it. It is noticeably better than O1, and much better than V11 or A2 (it lasts longer in use, takes an edge easier, doesn't hold a wire edge and grinds twice as fast and much cooler). If someone wants to buy those, they can just go get them on the commercial market. let's be realistic - very few of the chisels that are sold in the $80+ range are going to get used by anyone who can discern the difference, anyway. I've seen machined A2 chisels being sold on etsy for as much as $125-$150 each and the reviews just gush over them. It's not really the era of discerning workers, but just like you can make furniture nicer than you have to without too much extra effort, you can do it with tools. It only becomes prissy nonsense when the making is fiddly, the results absurdly expensive (or components) and there is a long laundry list of things you can't do with the tools. you can mallet half blinds with these parers indefinitely and the cost of materials in total is probably about $25-$30 per chisel with parers, including the belts and old cocobolo.
Very old tools were softer most likely for industrial reasons and to be usable with sandstone grinding wheels and slates/sandstones that were common when they were made. English tool hardness ticked up mid 1800s when the washita appeared. There are probably a dozen other reasons that older steel would be tempered softer in chisels, but not in files or razors - from adjusting straightness in manufacture to controlling grain size to dealing with steels 1% or below that laminate more easily to wrought iron. When I see the video that CW posted of making laminated chisels, there's definitely far more hammering to shape than I'm doing - workability at high heat matters more, and I'm using friable alumina specialty belts to grind - that's what's available now inexpensively, so those kinds of limitations don't exist. Workability with these, and sharpening/grinding, is about the same as Iles O1.
For wood - these chisels will probably outperform everything commercially available made of solid steel and they'd be less good if commercially heat treated. High speed steel still trims metal better (i have no idea why, but it does), but it grinds and hones slower - and isn't better working in wood unless you're cutting through nails or staples.