Which steel at what HRC holds the longest razor fine edge?

Londinium Armoury said:
I'm surprised H1 can even maintain a working apex at 7.5 dps, was it production spyderco or some work hardened piece?
I don't even know what to make of your graphs, why is H1 jumping all over the place like that, is it lost and in need of a map, haha.
Nice testing though, even if I don't quite understand the results.
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It's a regular Spyderco Pacific Salt. H1 at low angles produces a good edge that seems to be very durable.

Larrin said:
All testing has scatter and nothing ever looks perfect. I would recommend testing on a “log scale” meaning you test sharpness more at initial stages and then less often with more cutting. For example, test sharpness after 1 inch of cardboard, then 3 inches, 10, 30, 100, 300, 1000, etc. Initial blunting is faster and as you cut more the changes occur more slowly. But having scatter does not invalidate testing. No matter what the trolls and uninformed have to say about it.
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Thank you for the response, I'll change my testing method and keep this sort of thing in mind.
 
spoonrobot said:
It's a regular Spyderco Pacific Salt. H1 at low angles produces a good edge that seems to be very durable.



Thank you for the response, I'll change my testing method and keep this sort of thing in mind.
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Interesting, thanks for letting us know, I might take a closer look at the H1 offers, from the chemical composition I assumes it would hold a terrible edge, looks can be decieving I guess.
 
Thunderpants said:
Assuming you got one that arrived razor sharp, nothing is going to beat a Sandrin Torino or Lanzo. (If you got a blunt one - which is unlikely - you'd be in trouble because they're almost impossible to sharpen.)
Of course, these blades, being tungsten carbide, aren't steel as such, but they are extremely sharp and durable blades, which I think qualifies them for discussion. 71 HCR! I hope to get one soon so I should one day be able to speak from experience!
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Mine is over 80 HRC :) And yes , I can sharpen it .... I wonder how many miles of cardboard will cut;)
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Londinium Armoury said:
I'm about halfway through the article and I have a question. With the high wear steels losing their fine edge on the first stroke, you mention a 1 micron edge can't contain a 5 micron carbide. So if the carbides are not very fine then anything in the initial apex wont actually contain any of the 5 micron carbides at all, then the edge will stabilize itself at the 5 micron size carbides and form a thicker apex right? which will then be a working edge and continue cutting like that.
If I read that correctly is it safe to assume you want carbides as small as 1 micron to form the actual apex in order to hold that initial fine edge for long periods? Or in other words if your knife contains average micron size of 4, you shouldnt even bother trying to put a 1 micron edge on it to begin with because that is just going to wear away very fast because the actual apex doesn't even contain any carbides because it's simply too small to house the larger carbides.
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In my study, high wear resistance steels held their initial sharpness better than low wear resistance steels. That was contrary to expectation but results are results. In general we want carbide size to be as small as possible, however.
 
Natlek said:
Mine is over 80 HRC :) And yes , I can sharpen it .... I wonder how many miles of cardboard will cut;)
kOeKdDo.jpg

lnVxciq.jpg

A3SeNtm.jpg
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seriously - how do you hit 80??? is it steel or carbide or?
please give details...

for my 2 cents, I'd choose 3v at 10dps at about 61... I know some cpm-m4 might outperform that going upto 65, but imho 61+ is enough (and no, I personally wouldn't touch chip crazy zdp189, I know it 'could' be stable, but I just don't trust it)
 
Not very scientific, but edge holding for my collection tops out at whatever the HRC is of my HAP 40 Delica and ZDP 189 Endura.
Can't tell much edge holding difference between the two day-to-day for similar tasks, but they're both up there.

I know I've got some quality blades in S35VN that feel a bit soft compared to the Spydercos I mentioned, when sharpened on the
same diamond stone....and that same S35VN feels "ceramic" hard when compared to my 8Cr13 blades.

Real world use, I have a Manix in S110V that's a close second to the above mentioned Spydercos but I always seem to
at least get micro chips in the blade that kind of negate any razor sharpness that's left when I'd rather have a smooth feeling
through a cut on things like soft pipe insulation.

I know I've compared different steels on different blades at likely different HRCs, but again, real world, these are some of the most
common and affordable examples of these steels in a knife that can be compared. I look at it like if you custom ordered you could tailor
your "example" of a given steel, but if you're looking to keep it under $200 or so, generally, companies like Spyderco are where people
are going to source examples of these higher-end steels.

Just remember, if you're disappointed with a given steel type produced by one company, another company may take that same steel
and do much better things with it. Same wood, different carpenters, different results.
 
Youtube has an amusing vid of that charming Ozzy fella at Cedric & Ada trying to sharpen a Sandrin blade on various stones and wheels - which end up getting destroyed before the blade is affected in any way. An amusing few minutes if anyone here hasn't already seen it. Title is Sharpening Adventure: Tungsten Carbide.
 
No idea. the ability to hold a working edge is more important to me. "Razor Sharp" isn't needed for most cutting/slicing tasks (such as gutting and peeling a whitetail deer), and I don't shave with a knife (or anything else, for that matter.)
The old fashioned/"obsolete" steels like 1095, 440A, and 420HC work just fine for me, and hold an edge long enough to do what I need my knife for.

My most "advanced" steels are D2, S30V, and CPM154. They don't get used as much as my other knives though, so I really can't comment on their edge holding.
 
I can vouche for the zdp-189....had my endura 6+ months of every day use from twine, zip ties, packaging, cardboard....its cut everything and every day and I have yet to sharpen it and its still cutting through paper...its been a great steel for my uses highly recommend it....debating on picking up another endura in k390 or something else in zdp-189
 
afishhunter said:
No idea. the ability to hold a working edge is more important to me. "Razor Sharp" isn't needed for most cutting/slicing tasks (such as gutting and peeling a whitetail deer), and I don't shave with a knife (or anything else, for that matter.)
The old fashioned/"obsolete" steels like 1095, 440A, and 420HC work just fine for me, and hold an edge long enough to do what I need my knife for.

My most "advanced" steels are D2, S30V, and CPM154. They don't get used as much as my other knives though, so I really can't comment on their edge holding.
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That's why I like Pete's testing (Cedric and Ada). He goes until the knife won't cleanly slice paper. That's more real world experience to me, and most steels, even lower end, hold up just fine. I still like my blades sharp enough to shave arm hair, but even if they don't they still will slice things just fine. But then I touch them up anyway... Just because!

Have a rough ryder fixed blade coming with my bk16, it's in 440a. Going to be fun to see how it holds up. I think it should do just fine though.
 
I'd probably rate my Military in S110V as the top edge holding -- albeit that is with a fairly coarse edge. For a real fine edge I'd have to go to one of my blades in 52100, like my Marble's Campcraft or my Ivan Campos Scandi grind blade in 1070.
 
I did some edge retention testing to see how fast a knife loses its ultimate sharpness and fails the 3 finger test, and I used cutting into tissue as a way to demonstrate ultimate sharpness of the apex has been lost.
I tested 2 types of S30V, 14C28N, 12C27, S35VN, Cryo treated 154CM, D2, K390.
I came up with a different way to dull the knife edge in a faster manner than cutting rope or cardboard. I will post the stroke numbers here in case anybody is too busy to watch the video and just wants the raw numbers. But you can watch the video to see what material and method I used, I ran the test once on camera and once off camera and the numbers were actually very consistant, almost identical actually.

Spydercos K390 - 8
Spydercos S30V - 5
Benchmades S30V - 4
Kizers S35VN - 4
QSPs 14C28N - 4
Hogues Cryo treated 154cm - 4
Ontarios D2 - 3
Spydercos 12C27 - 2

These numbers represent the number of strokes along the entire cutting edge with as close to the same amount of pressure as I could put down onto a tough resin synthetic like material until the blade would no longer make cuts through tissue paper. The blades could still shave and cut regular paper after the strokes, they just lost their ultimate level of tissue cutting sharpness.

 
It appears that the length of the edge should figure into any knife edge test. Wouldn't an Endura with a S30V fine edge last longer than a Delica with a ZDP-189 with a fine edge because of its longer blade edge? I'm thinking of normal slice cutting, not push cutting. Thoughts? Or if both had the same ZDP-189 fine edge wouldn't the Endura edge last longer just because it is bigger. Most knife users are slicers, not pushers.
 
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Not a pusher, just a serious recreational user. For me, and with occasional dalliances, the ZDP-189 edge in my Kershaw Shallot composite has been my drug of choice for the last 12 years. Shows no signs of wear, and holds a good working sharp for a LONG time.
 
thanks to everyone for sharing your experiences with zdp189, I know it can be good, but like I said I've been shy on any serious investments in it due to the overly chippy nature or early problems reported...

I know I should be more open minded, esp since high end companies like rockstead use it as their main 'stainless' option
(as well as some spydy's and other makers)

personally I am enjoying my spydy with cpm-m4 (in the gb2) too much to bother going for higher edge retention... like you, I've been failing to make it dull after a lot of cutting tasks ; )
 
My Spyderco Michael Walker in ZDP-189 was initially chippy. It has a fairly thin, hollow grind. After a few sharpenings, it hasn’t chipped on me, yet. My other ZDP knives, a Delica and a Caly 3, never chipped at all. Those are both FFGs. I haven’t carried or used it as much as other models. I can’t answer many questions about initial sharpness and keeping that sharpness. I can tell you that one night I got drunk with a chick. I shaved her legs and mine with a Super Blue Caly 3. That thing was still a razor the next day. Seriously thought, it happened that way.
 
afishhunter said:
I don't shave with a knife
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This strikes me as humorous. I DO shave with a knife. My favorite straight razor is a random carbon steel Chinese 7/8 full hollow straight tuned by Rup Razor. My second favorite is a Dovo 5/8.

But then I tune them up on a strop before each shave.
 
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NapalmCheese said:
Think strikes me as humorous. I DO shave with a knife. My favorite straight razor is a random carbon steel Chinese 7/8 full hollow straight tuned by Rup Razor. My second favorite is a Dovo 5/8.

But then I tune them up on a strop before each shave.
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That old/ancient, frightening/scary to look at/see, really ugly bearded thing in my avatar picture ("ick-sure"?) really is me.

I use my no-name "Gold Dollar 1996" (unless that's the brand name) carbon steel Chinese(?) straight razor for a patch knife, when shooting my muzzleloading pistol and rifle, when I don't have pre-cut factory made patches. :D (just like the "mountain man" of old did.)
I'll never actually shave with it. I gave up that dirty, nasty, vile, obscene. expensive habit in 1988,when I got divorced. Why in the name of any planet, solar system, or demon, would I want to start again? So I'm not going to worry about "ruining" the edge by cutting pillow ticking. Besides, I'm pretty sure cotton is softer/not as "tough" as hair. A Rhino's horn(s) are nothing but a single big (no doubt dirty) hair, made of the same stuff our hair is. I don't think anyone would honestly call a Rhino's "horn(s)" "soft". :)
 
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