Coffee thoughts... M390

Grain structure is more important than hardness (within the confines of this discussion.) Same steels at the same hardness can have different microstructures.
 
If we're talking Benchmade I have some of their older M390 (581, 586, various 707/710/730 LEs) and in blade shapes with good geometry I've been pretty happy with it.

730's never going to be a slicer anyway but I've used an M390 710 hunting for over a decade now and been really happy with its performance. 581/586, similarly pretty happy. They don't seem to give up too much to the wider assortment of M390/204P/20CV Spydercos I also have floating around.

Iirc there was some kerfuffle around the Bailout in a carbon steel (3V? M4?) being too soft and they corrected it in future runs. I have felt that some of their older (2015 and earlier) M4 was a little soft but again, it's on models with blade shapes/profiles ground more for toughness anyway.


I guess I think they can and should do better than 58-61 for what they currently charge, but if it was one of their models that I really liked and could convince myself to shell out the money I would probably not be concerned about the HT on one of their M390 or 20CV blades.

Third, fourth, and fifth are M390...used to be easier to pick up multiples when they weren't $450 and I didn't have a wife and kid 😂😅

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R.Russell said:
To put things in perspective, Carothers makes batches of lets say 20 -100 knives and they list an exact HRC or a range of 1 point from what I've seen.

I'm guessing this is a very modest operation compared to the larger knife companies.

How is a small shop getting more consistent results? Maybe they put more effort into the product and QC than into advertising, etc... ????
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I don't see your logic here.

Smaller profuction means less variance and less amount of work to put into the quality control. Carothers knives are not exactly cheap neither. Each of them is as expensive as a custom made-to-order.

Mass production companies can't always test 1000s blades at once due to time constant. Mass heat treatment also gives different results even in the same forge. The different placement of the blades and heating elements can all play on the final quality. Naturally to make money out of mass production, you have to sacrifice the quality somewhat. Otherwise, mass production is not as easy as it seems.
 
I’m sipping some coffee now and my thoughts are that over the last few years I’ve noticed that some of the high hardness knives in the 64-65 hrc range were being reported as having chipping at the apex. Im guessing that the knife manufacturers backed off the hardness in an attempt to reduce the chipping problem and warranty returns . I know there’s many people out there who want maximum edge retention in a folding pocket knife and I understand that but with what I’ve learned is that even when the hardness isn’t up there it still performs very well if not better at say 61-62 depending on the metal. As long as it doesn’t chip or roll the edge it should cut very well and im happy.
 
270ultimate said:
That would be a FANTASTIC shot, if only the clips were mounted on the correct sides…
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Brother if you're here for the axis lock you're just going to have to accept there will be extra southpaws around 😂

But I did switch it to a purple anodized deep carry clip so now it makes more colorful pictures.

M390, M390, S30V. (Hunting knife, wedding knife, I'd rather have a Manix 2 knife)

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Deino said:
I don't see your logic here.

Smaller profuction means less variance and less amount of work to put into the quality control. Carothers knives are not exactly cheap neither. Each of them is as expensive as a custom made-to-order.

Mass production companies can't always test 1000s blades at once due to time constant. Mass heat treatment also gives different results even in the same forge. The different placement of the blades and heating elements can all play on the final quality. Naturally to make money out of mass production, you have to sacrifice the quality somewhat. Otherwise, mass production is not as easy as it seems.
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Carothers smallest and most recent offering to my knowledge is their EDC 1.2, it had a cost of $400, not sure if that included tax and shipping. So the price is comparable. And it’s full tang with a 3” blade. So roughly 7” of the higher cost steel.

Obviously making thousands of knives increases your workload and allows for more errors. But you’d think the bigger companies could actually afford to scrap knives that didn’t make spec, something a smaller shop couldn’t necessarily do.

It seems the consensus is that the tolerances of 58-61 is acceptable to most guys here, so be it. Appreciate the banter
 
R.Russell said:
It seems the consensus is that the tolerances of 58-61 is acceptable to most guys here, so be it. Appreciate the banter
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Sorry if I seem overly lackadaisical about it. It's a reasonable question for the amount of money knives cost these days. And manufacturers have responded to this sort of feedback (when enough people get vocal enough) by bumping hardness before - BM Bailout as previously mentioned, CRK S35VN, etc.

M390 in particular got dragged through the mud about five years ago with some ginned up youtube "content" bull**** where it turned out some youtubers can't use hardness testers and American and European OEMs are, in fact, hitting their advertised ranges. But, your question was about whether or not it was an appropriate range, not whether or not it was an accurate one.

A four-point range does seem a little wide, and 58 does seem low for M390 assuming you're buying for wear resistance and not toughness. Seeing that range on Benchmade 535BK-4 or 710-25 specs is disappointing. It would be good to see them tighten up and raise that range for this steel.

However, for Benchmade in particular, if I could get over the rest of the price it wouldn't stop me from buying a model I liked because I've had good results with their M390 in the past and trust that current performance is similar. A Chinese OEM with the same range and yeah, I'd be looking a lot more closely at performance reviews first.

Times like these I start to understand why Spyderco prefers not to advertise a range and just let their reputation for steel performance do the talking. 😅 (For what it's worth, crowd-sourced measurements of Spyderco's M390/20CV around the time of that youtube drama suggest they aim for 60-62: https://forum.spyderco.com/viewtopic.php?t=83847)


Off my M390 soapbox now. 🙃
 
I seriously doubt the BBB heat treat on the 15v would allow a 4 point margin. Or anything from that company honestly.

My point is you vote with your dollars. Me personally, over a certain dollar amount I want to know what im getting. 4 points seems like a wide margin. Even Kershaw holds a tighter tolerance than that. They do magnacut at 62-64. Maybe had more to do with where theyre ok with the numbers and if your accepting of it. For instance Kershaw having a 3 point allowance isn't crazy good, but I was happy with 62 or 64. I would not have been happy with 60-62 and if they'd chose that I would not have bought the knife. I dont think production is an excuse, other production companies are doing great heat treats. Now benchmade, I dont like how low theyre willing to accept the numbers at, so I dont shop them.
 
Sometimes the 3-4 points of difference in hardness is vastly overestimated…

According to Larrin test, There are only 5.8% increases in CATRA edge holding between 440c at 57HRC vs 62HRC (425 vs 450 cuts)

Even have seen many people whine about Magnacut @60 being as a subpar steel… just a couple decades ago 60HRC are considered to be a pretty numbers for most steel.
 
Having put various knives at various (tested) HRCs through everyday use, I have to say I definitely notice increased hardness. My current EDC is a Demko AD 20.5 with a MagnaCut reblade by Transparent Knives treated to 54.8. In comparison, I own knives in MC treated to 63, and another to 61-62. I’ve used and sharpened them all. While I’m not going to complain about what I choose to buy, there is definitely a noticeable difference. I’ve also had knives in “premium” steels with such bad heat treats that they lost their edges after a single cardboard cut. Unlisted treatment and hardnesses. That is unacceptable in my books.
 
Leo Greer said:
No. Brian pushes the limits on the blades he does. Hard, thin, and hollow are the name of his game. I think the one I have measures out at 0.06” behind the edge.

He has some in his archive that have come out over 55.
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Huh, I was unaware. I'll have to take a look.
 
Leo Greer said:
Having put various knives at various (tested) HRCs through everyday use, I have to say I definitely notice increased hardness. My current EDC is a Demko AD 20.5 with a MagnaCut reblade by Transparent Knives treated to 54.8. In comparison, I own knives in MC treated to 63, and another to 61-62. I’ve used and sharpened them all. While I’m not going to complain about what I choose to buy, there is definitely a noticeable difference. I’ve also had knives in “premium” steels with such bad heat treats that they lost their edges after a single cardboard cut. Unlisted treatment and hardnesses. That is unacceptable in my books.
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Leo Greer said:
No. Brian pushes the limits on the blades he does. Hard, thin, and hollow are the name of his game. I think the one I have measures out at 0.06” behind the edge.

He has some in his archive that have come out over 55.
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I think you might want to recheck those numbers. Neither 54.8 nor .06” BTE are acceptable results.

I don’t think many people think in terms of ‘thousandths of an inch’, and maybe you’re one of them, but .06” is nearly 1/16th of an inch (.0625”). Most knifemakers wouldn’t leave an edge that thick BEFORE heat treatment, and 54.8 RC is nothing short of abysmal for nearly any modern knife steel.

Perhaps you mean 64.8 and .006”?
 
Matthew Gregory said:
I think you might want to recheck those numbers. Neither 54.8 nor .06” BTE are acceptable results.

I don’t think many people think in terms of ‘thousandths of an inch’, and maybe you’re one of them, but .06” is nearly 1/16th of an inch (.0625”). Most knifemakers wouldn’t leave an edge that thick BEFORE heat treatment, and 54.8 RC is nothing short of abysmal for nearly any modern knife steel.

Perhaps you mean 64.8 and .006”?
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That is correct, not sure why I misread the numbers that badly. :rolleyes:

I'm gonna keep the original post the same so hopefully some folks can get a good laugh out of my goof. 😂
 
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Wouldn't it be cool if the bigger manufacturers offered a choice of a tuff or hard varience in popular models? Same knife, same steel, two options. Perhaps slight variations in the grinds to lean into the attributes. They could even offer two separate warranty parameters to cover their exposure.

*Edit After considering my idea here, I've realized it's just a much more complicated version of the same knife in different steels. lol
 
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