rockwell hardness....or not?

Randall

Ray Mears
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This guy is great for testing and advertising rockwell hardness of various knives. Apparently many manufacturers using m390 in particular have been way out. Just like the supermarkets, it's always less, never more. This dude views the ideal hardness of m390 at 62, surprise surprise as does an m390 enthusiast here - waveman. It's a rarely seen figure.
 
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Wave Man

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I have posted about this on ABF, and have been met with criticism at every post. Seems like most people do not like to talk about the minutiae of their knives.

I am happy to continue about this subject.
 

Randall

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Like you, I wouldn't call it "minutiae"; it's fundamental to a well made knife. For many knife owners though, it will probably never be noticed; owners opposed to users. It looks to me that most members here (and I'm a fanboy) appreciate your posts waveman, but I'm a recent arrival and sporadic at that. You're definitely one of the most knowledgeable and interested knife collectors I know of. Your posts here are well thought out and presented - I know those things take time and effort.
 

Thrud

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I’d be interested to hear more.
I agree with Randall’s comments above; it is great to have experts like Waveman on the forum and appreciate the effort that he puts in to inform others.
 

Wave Man

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thanks fellas, the HRC issue is disappointing. I would hardly call myself an expert, I am just an enthusiastic amateur.

LTK (YouTube knife review channel) has been doing a heap of testing (HRC and steel, seeing if the steel a manufacturer says they are using is actually the steel that is used) and has found a lot of manufacturers aren't delivering M390 at the optimised range (as stated by Bohler) which is HRC60-62. Many of the knives tested are falling short, usually in the 58-59 HRC range.
Through cut testing (other channels on YouTube) the difference in edge retention between HRC 58-59 and HRC 62 is double (you will get double the edge retention figures, both fine shaving edge and working edge when M390 is HRC62)
 

Randall

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It's interesting, and kind of sad, that Nick Shabazz has weighed in pretty much dismissing ltk as a knee jerk, uneducated reaction. I like nick's videos, but I think he is performing a disservice here. And it really sounds as though he hasn't actually seen the video or knows how the testing was done. He alludes that the testing isn't done by professionals and that it is possible that the tool for testing is out of whack. The testing was actually done by someone in the industry who does this all the time as his job. And the results are fairly uniform for the different manufacturers - except for one manufacturer where the variance was huge. It is industrial measuring equipment. Usually if an instrument like that is out, it is too high or too low, not random - the instrument in question is quite basic and simple; it applies pressure to the metal until the metal gives. I applaud LTK; without his input, and those like him (esp Cedric and Ada), we wouldn't know. We'd just think "gee, I'm not that impressed with this knife". Ultimately, business is business, and they will do what they can to improve their profit margins. A lower hardness means lower temperature heat treat which means less energy used, easier to cut and grind, less wear and tear in the factory, generally the steel is much easier to work with. This hasn't been an issue with small custom manufacturers where there is pride and passion. It is a handful of knife manufacturers but they are mostly high end and expensive - benchmade and lionsteel for example. That's pretty crap - these guys charge top dollar and can't do what at least one chinese budget knife manufacturer exceeds at (ganzo knives). And ganzo knives are generally around 10 to 15% of the price! The one point that Nick does convey in a convoluted way, is that hardness is a balance - kind of obvious. For example, those ganzo D2 knives measured at around 62rh is at the top of the range of recommended hardness (55 to 62). I can't imagine anyone preferring 55 to 62, unless you want to practice sharpening knives - softer steel is easier to sharpen. If you go higher than the recommended range, say 63, you could be in file territory, very hard and brittle, the possibility of chipping and breaking if abused, say batoning, levering, or some other non knife uses. And the knife is going to be harder to sharpen, because the steel is harder! But you won't have to sharpen it so often and it will last longer - all kind of obvious. So, ganzo are pushing the limits here it would seem. There is the chance of a pendulum effect or over reaction. That is that manufacturers start going too hard rather than getting it right, in response to the knee jerk and uneducated response of the knife enthusiast market that harder is better. Really though, enthusiasts in any area, are fairly educated and knowledgeable - something that Nick doesn't seem to understand. Hopefully manufacturers will advertise the hardness they use along with their justification of it for the knife's purpose. For example, a survival type knife that is thicker and heavier may have a slightly lower hardness so that it doesn't break or chip when used for batoning or levering or cutting tin cans open.
 
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Wave Man

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I saw Nicks response and agree Randall, he basically dismissed the entire issue.

The bloke who is doing all this HRC testing has had his work independently verified so his results can be trusted.

The thing that annoys me is M390 is marketed as a high edge retention super steel, and when delivered at HRC 58-59 it is no better than say S35VN (HRC 60) in regards to edge retention and S35VN would be more tough in that scenario to boot. That's not running S35VN down, but we pay a premium for M390 and we are basically being ripped off, and most people would be better off going with S35VN (HRC 60) than by getting M390 at HRC58-59.

I have 23 M390 flippers and freely admit I probably bought into the M390 hype somewhat, but I also made the conscious decision to exclusively EDC M390 because of its reputation for extreme edge retention, and most of them probably aren't at HRC 62 and have that extreme edge retention.

From what I know M390 remains ductile (isn't brittle and resists chipping) at HRC 62 (as shown from several cut tests). Also Bohler (the company that produces M390) recommends M390 to be with in a HRC range of 60-62. Some custom knife makers in the US are testing M390 (and 20CV) upto HRC 64 with some very promising results.
 

Randall

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You're bang on. You shouldn't have to want anything from that end (the high end) of the knife spectrum. They should already be at the upper limits of the steel. It shouldn't be your concern. M390 is a logical choice for anyone, depending on their budget of course. Who gets into knives and after a while doesn't want that high end steel? Even I, budget man, spent a small fortune on a vanadis 4e knife. I don't see it as hype, it's all real, but like LTK says, only if they do it right. The problem has been those few manufacturers letting down their clients. Mostly though the others could push their numbers up a bit, rather than being mid range. The greater disrespect is that it is educated and discerning knife enthusiasts like you who really appreciate and pay extra for that premium product. Hopefully though your collection is fine. No mention of zt. In fact lionsteel looks the worse, kizer is hit and miss (I have 2 kizers). Cold steel - a large part of your collection is generally in the high end of the range - I think we both knew that, at least anecdotally, with their aus8a knives. Civivi looks good except for one 9CR18MOV - I'm guessing you don't have that one :D. I'm surprised at spyderco - hit and miss - I wouldn't have guessed that. Not surprised at benchmade - tis a pity though, they have a cult following and are US manufacture. Maybe Nick has shares in benchmade? Your collection, the few parts I've seen of it :), generally looks good. I know you'd like higher than mid range numbers for all your knives though - so would I; and that's still the pity.
 
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Wave Man

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mate you are exactly right, I want all of my M390 EDC folders at HRC62, to take advantage of the extreme edge retention that M390 is capable of when hardened and tempered to that HRC. It is a simple expectation that the manufacturer will produce a folder at its optimised hardness.

I love this vid from Banter 247,

I like Banter, he is a straight shooter and doesn't have a lot of bullshit in his vid, and I have to say I am often in agreement with him. He also has a lot to say that is IMHO very apt to this discussion.

and why I watch YouTube testing channels

put simply they are doing the testing I would love to do but don't have the resources or time.
 

Wave Man

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I see TuyaKnife has just recalled it latest offering the Kingsman, testing showed its M390 blade had a HRC of 59.8 and because of all this kuffel on YouTube they are rehardening them to HRC62 (or thereabouts) so companies are starting to listen and we are seeing positive results. I hope eventually you won't be able to get a M390 outside of the HRC60-62 range, and some customs as high as HRC64.
 

Randall

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The funny thing is all those US$24.00 ganzo's came back at 62rh for the D2!
 
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Randall

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The next whinge should be random grind angles 🤣. That's pretty common too. Go and fire up LTK waveman 😂
 

Wave Man

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The next whinge should be random grind angles 🤣. That's pretty common too. Go and fire up LTK waveman 😂
agreed, and proper secondary grind bevels (for pocket knives we should have 17 degrees and combined with a flat or hollow grind at most so as to get a good behind-the-edge measurement so as to make a slicey knife) then good/perfected pocket clips.
 

Randall

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agreed, and proper secondary grind bevels (for pocket knives we should have 17 degrees and combined with a flat or hollow grind at most so as to get a good behind-the-edge measurement so as to make a slicey knife) then good/perfected pocket clips.
See, you do have all that knowledge at hand, and more I know. I bet you rattled that off in a nano second :)
 
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