H-2 Steel, Knife Steel Nerds Article is Out

[James Y]

I read a post somewhere (probably not on this forum) where someone stated that H1 doesn't hold an edge at all, in either PE or SE. Maybe he was trying to cut cinder blocks with it; I don't know.

Jim

[cabfrank]

Or maybe he was repeating the narrative and didn't try cutting anything at all.

[James Y]

Or maybe he was repeating the narrative and didn't try cutting anything at all.

Quite possibly. There is a lot of that.

Jim

[Red Leader]

...
Probably the only way we’ll see all this put to bed is a head-to-head comparison between 4 knives:


SE H1
PE H1
SE High wear resistance tool steel
PR High wear resistance tool steel

…and then do the testing on all 4 and compare results. I would be looking for a comparison between the SE/PE for each steel and how much longer, in percentages, the SE lasted against each comparitive steel’s plain edge sibling, and then of course just the raw numbers - how many cuts could each one make, period?

Maybe it would tell us there is something special about SE H1, or maybe that it would tell us that while SE in H1 is indeed excellent, it is still outclassed by SE in tool steel with better baseline edge retention.

I for one would love to know.

But, ...

How would these PE variants be sharpened? Would it be to a high-grit finish or even honed or would it be toothy sharp with only a low grit used? Would any of that make a difference?

For the results to be definitive, they may also need to be thorough. Sorry.

How about a hybrid? 400 grit on one side, 12000 on the other??

Just kidding. For all intents and purposes, working edges - I mean, maybe use the same grit for the PE and the serrations as well? Or just start w/ factory edges and go from there? @Steeltoez83 has shown through his exhaustive testing that moving past the factory edge can yield higher performance results. I wonder how that could also work for serrations as well?

In any case, we live and work with these edges day in and day out, so some leeway would have to be acceptable. If the test was repeated several times, I do think some pretty basic themes would have to emerge.

[Larrin]

Supposing that's the case, it still comes back to what's special about H1/H2 versus other steels because the delta between serrated and plain edge is significantly higher than with other steels. If it was solely geometry, we'd see similar deltas.

Serrated edges are less sensitive to the wear resistance of the steel, so H1 and H2 still do well like other steels. On the other hand, plain edges do poorly because of low hardness and wear resistance. Thus, the difference between the two is large.

[vivi]

Supposing that's the case, it still comes back to what's special about H1/H2 versus other steels because the delta between serrated and plain edge is significantly higher than with other steels. If it was solely geometry, we'd see similar deltas.

Serrated edges are less sensitive to the wear resistance of the steel, so H1 and H2 still do well like other steels. On the other hand, plain edges do poorly because of low hardness and wear resistance. Thus, the difference between the two is large.

that doesn't explain why there's a bigger % of edge holding difference between PE H1 and SE H1 vs PE S30V and SE S30V, which is what we're all talking about.

[Larrin]

that doesn't explain why there's a bigger % of edge holding difference between PE H1 and SE H1 vs PE S30V and SE S30V, which is what we're all talking about.

I think if you read what I wrote more carefully you will find that it does answer that question. If that doesn’t work here are some made up numbers. Let’s say that in the plain edge test H2 was 250 mm and S30V was 500 mm. The higher hardness and wear resistance of S30V gave it higher edge retention. Then in the serrated test the serrations greatly change the result and the wear resistance of the steel is less of a factor. The serrated CATRA test is twice as long and the serrated edges don’t lose much cutting ability over the course of the test so the numbers are larger. So for example let’s say S30V was 1500 mm with a serrated edge and H2 was 1000 mm. The S30V saw a 3x increase while the H2 saw a 4x increase. Because wear resistance matters less in the serrated test the lower wear resistance steels see a greater improvement by using serrated instead of plain edges.

[vivi]

that doesn't explain why there's a bigger % of edge holding difference between PE H1 and SE H1 vs PE S30V and SE S30V, which is what we're all talking about.

I think if you read what I wrote more carefully you will find that it does answer that question. If that doesn’t work here are some made up numbers. Let’s say that in the plain edge test H2 was 250 mm and S30V was 500 mm. The higher hardness and wear resistance of S30V gave it higher edge retention. Then in the serrated test the serrations greatly change the result and the wear resistance of the steel is less of a factor. The serrated CATRA test is twice as long and the serrated edges don’t lose much cutting ability over the course of the test so the numbers are larger. So for example let’s say S30V was 1500 mm with a serrated edge and H2 was 1000 mm. The S30V saw a 3x increase while the H2 saw a 4x increase. Because wear resistance matters less in the serrated test the lower wear resistance steels see a greater improvement by using serrated instead of plain edges.

back to the same question:

Why don't steels like 1095, 420, aus4 and other low edge retention steels show a similar % jump between PE edge retention and SE edge retention?

I've used a lot of SE 1095 knives for example, and the edge retention isn't good. It's not much better than PE in my experience.

H1 shows a greater disparity between the edge types than those steels do in my experience and apparently in spydercos testing.

-------------------

Furthermore I'd also say H1 PE by itself shows a greater edge retention difference between a thick, polished edge and a thin, coarse edge.

I've tested that style edge on many steels. On every steel the edge retention when slicing abrasive media like cardboard jumped up quite a bit, but with H1 I found the difference even more dramatic.

Of course something like K390 sharpened the same way will still blow it away in edge retention tests if corrosion isn't a variable,but H1 PE with a toothy edge still has way better edge retention than I expected.

[phaust]

Supposing that's the case, it still comes back to what's special about H1/H2 versus other steels because the delta between serrated and plain edge is significantly higher than with other steels. If it was solely geometry, we'd see similar deltas.

Serrated edges are less sensitive to the wear resistance of the steel, so H1 and H2 still do well like other steels. On the other hand, plain edges do poorly because of low hardness and wear resistance. Thus, the difference between the two is large.

Makes sense. Have you happened to have tried or know a reference who/that has tried both edges with another low hardness and wear resistance steel? With another data point that might seal the case.