The "Ask Nathan a question" thread

xxwarderxx said:
M390 and other steels with similar properties seem to be the go-to steel for premium folders.

What’s your thoughts on these steels compared to the Elmax, D2, and AEBL currently seen on CPK blades and does it have any place in a future CPK offering?

I’m also curious how much more performance you could get out of them than the current heat treats offer.
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The Shiro I'm carrying uses M390. I think I had it in a Reate I lost too. It's not great. No better than the S30V in the Sebby I was carrying before that, and that didn't set a very high bar.

I have experimented with the alloy here and have done heat treat trials with it. I don't really like it. It's not bad, but it's not great. I suppose the abrasion resistance is very good as is the corrosion resistance, but it doesn't stay very sharp in real use as well as alternatives such as Elmax. I think there's just too much alloy and carbide for the matrix to properly support a knife edge. Mushy crumbly when I've used it.

I think one reason folks have mixed results with it is because, in my experiments, it was unusually sensitive to quench rate. The Rockwell hardness numbers they show in the data sheet are what I've seen in atmosphere quenches but my testing of the alloy here I got significantly higher numbers with faster quenches. This degree of sensitivity and the variation you will get from one setup to another and from one geometry to another means that the optimized heat treat for it may be illusive and inconsistent. Most volume makers waterjet, heat treat, then grind. That solid cutting edge area was thick during the quench, and it was a nitrogen gas quench in the oven which isn't real fast to start with, so I don't think they're always getting the quench rate that alloy needs. Not ideal for the alloy and would explain why it doesn't perform great in the factory knives I've used.

So, to me, I think it's probably an outstanding material for it's intended uses, but for cutlery I've seen better real world performance out of regular S35VN. People put too much credence in those card stock cut tests and perhaps knives with obtuse edges or subject to light use. I played with it and didn't get the edge stability I want and haven't messed with it again.
 
Nathan the Machinist said:
The Shiro I'm carrying uses M390. I think I had it in a Reate I lost too. It's not great. No better than the S30V in the Sebby I was carrying before that, and that didn't set a very high bar.

I have experimented with the alloy here and have done heat treat trials with it. I don't really like it. It's not bad, but it's not great. I suppose the abrasion resistance is very good as is the corrosion resistance, but it doesn't stay very sharp in real use as well as alternatives such as Elmax. I think there's just too much alloy and carbide for the matrix to properly support a knife edge. Mushy crumbly when I've used it.

I think one reason folks have mixed results with it is because, in my experiments, it was unusually sensitive to quench rate. The Rockwell hardness numbers they show in the data sheet are what I've seen in atmosphere quenches but my testing of the alloy here I got significantly higher numbers with faster quenches. This degree of sensitivity and the variation you will get from one setup to another and from one geometry to another means that the optimized heat treat for it may be illusive and inconsistent. Most volume makers waterjet, heat treat, then grind. That solid cutting edge area was thick during the quench, and it was a nitrogen gas quench in the oven which isn't real fast to start with, so I don't think they're always getting the quench rate that alloy needs. Not ideal for the alloy and would explain why it doesn't perform great in the factory knives I've used.

So, to me, I think it's probably an outstanding material for it's intended uses, but for cutlery I've seen better real world performance out of regular S35VN. People put too much credence in those card stock cut tests and perhaps knives with obtuse edges or subject to light use. I played with it and didn't get the edge stability I want and haven't messed with it again.
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Thanks for sharing your experience.

I haven’t been a massive fan of M390, finding S90V lasts way longer between sharpenings and Vanax performs equally well but needs a touch up equally quickly if not a little more often. It’s ridiculously corrosion resistant and pretty cool composition wise.

But after how many bunk S35VN folders I’ve had, and the couple kitchen knives in the same the M390 in my Shiros is better for household tasks in my use.

I wonder if your older Shiro has an older HT protocol that is outperformed by the newer ones in some way you can’t compensate for but you messing around with it should have improved it as far as I know.

I wouldn’t worry too much regardless. M398 is out now.
 
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This is a very mundane question, but I want to drop some weight from my fk2 by switching my g10 scales for micarta. I don't have any micarta scales, though, so I need to find some. Does CPK ever do sales of extra scales or should I just ask around in the sales thread?
 
the Diskin I carry most every day for the past few years is Elmax, and the edge holding is unlike any other knife I've used. Harder than woodpecker lips, so it's not an easy sharpen, but unlike a lot of high hardness steels I've used it doesn't crumble
 
Box_Opener said:
This is a very mundane question, but I want to drop some weight from my fk2 by switching my g10 scales for micarta. I don't have any micarta scales, though, so I need to find some. Does CPK ever do sales of extra scales or should I just ask around in the sales thread?
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Yes, we offer extra scales. They're very affordable. You can contact Jo and see what is available.
 
Good Morning Nathan, was wondering if the Double Red Canvas recently introduced will remain Red with use ( (red resin, red textile, looks maroon), or turn a brownish color with use (like Maroon)?

Thanks

Tom
 
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Nathan,

I missed the pre-sale on the heavy duty medium choppers. Do you have any idea when they may be up or if there will be any to put up for sale on the forum?

Thanks
 
shaving sharp said:
Nathan,

I missed the pre-sale on the heavy duty medium choppers. Do you have any idea when they may be up or if there will be any to put up for sale on the forum?

Thanks
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A response from Nathan on 4/23/2019 to a similar Q:

https://www.bladeforums.com/threads/the-ask-nathan-a-question-thread.1425245/page-134#post-18961521

A few days ago Nathan had stated that there will be an HDMC to show at this upcoming Blade (will there be some actually for sale? Perhaps, but I'm not sure!). Also I had asked a related question about HDMCs preorders planned shipping out about a month ago and Nathan had responded something like "in a couple of month".

#imstillnotnathan
 
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