Hand Tools Archive
We could probably do these now (I could) with a scope, but I have zero interest in doing them because I don't disagree with any of them based on stuff I've used.
Now that we've had these discussions and I've personally had much more experience with each of these irons, the only results here that I don't match are the eskilstuna (my berg iron is hard and chippy and fails early - it doesn't feel that hard on the stones, and may just be a rare dud).
The knight iron that I commented about is apparently cryo treated. By every standard you could think of, it at least matches the A2 irons, but it's actually better.
The wear bevel is the same width as an A2 iron, but it is *miles* cleaner, and would cut much further into its wear cycle without even discussing surface quality. It would do that because even though it's the same length, the actual edge itself is less blunt.
I noted when I sharpened these irons that they abraded slowly on the stones, and attributed that to hardness, but never had them checked.
You can see they fare much better than the hock irons.
When I got into this hobby, a hock iron was described as an automatic improvement over a stanley iron, and in some cases, some of the old stanley irons (even the laminated ones) don't wear that long, but the average later stanley iron without rounded corners will generally hang even with hock's high carbon steel, wear a little differently (longer wear, i'm sure, but less defect and chipping) and be nicer to use.
Context of those hock irons early on may have been the stanley irons from the 70s that were rounded. Those are terrible irons. On a ruse, I bought one of the last sheffield stanley planes last year. It was a terrible plane for a few reasons, but most due to lack of care (the adjuster didn't even fit in the slot on the cap iron - it was too thick and the iron sat suspended on the adjuster above the frog). It, however, has a perfectly fine (actually quite nice) iron that's reasonable hardness, so i can't make a blanket statement that all irons after the round topped irons appeared are junk.
I don't know that I have any hock irons floating around (at least not in carbon steel). I sold one plane and one kit, and don't remember if I had an extra. If I did have an extra, it'd be interesting to have them hardness tested. They wear well, they're hard, and they don't chip.
If someone posed the question on another forum, "which iron lasts longer between sharpening cycles, a good A2 iron or Steve' Knight's O1?", I'll bet most people would answer incorrectly.
Steve's O1 is on par with the rikizai tsune. It's too bad once he got out of business, he didn't introduce his commercial hardening service to slotted stanley irons. They'd probably be as good as anything that we can reasonably get.
One last aside, as pat mentioned, brent doesn't really know anything about stropping. he got me off on the wrong foot regarding that, too, as someone mentioned his study to me, I didn't see it, and they said all stropping degrades an edge. I think I said something to Brent via email about that once (I know I said something to him about double irons). He's fairly dismissive of suggestions (and I offered them politely).