The "Ask Nathan a question" thread

Good afternoon NtM...I read your post #2741 about m390, ht, et.al. ... it was very informative, thanks.

Sounds like AEB-L <with CPK optimized anneal/HT/quench protocol ;)> is getting close to the holy grail of "stainless properties with tool steel performance & sharpen-ablility..."

I know there was the limited aeb-l UF recently.... but what can we expect out of CPK offerings in AEB-L in the future? Something small & slicey and widely available I hope... Thanks
 
"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. "
 
"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. "

tldr :D
 
I read and actually understood all of this one ... so did I get bitten by a radioactive spider and am now smart? ... or was that just Nathan dumbing it down so I could follow? ...

I'm either amazed @ me ... but probably more likely should just nod and thank Nathan ...

from my past ... I'll go with the second choice :p
 
"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. "

Great read and info:thumbsup:
Thank you Nathen!
Cheers
 
I read and actually understood all of this one ... so did I get bitten by a radioactive spider and am now smart? ... or was that just Nathan dumbing it down so I could follow? ...

I'm either amazed @ me ... but probably more likely should just nod and thank Nathan ...

from my past ... I'll go with the second choice :p

You must've stayed at a Holiday Inn Express!
 
Nathan, do you also buy any knife or knives for self when at Blade? Are there any tables/makers whom you look forward to frequenting if you get spare time?

We are on the road, but there are a lot of makers we look forward to seeing. Billy Mace Imel, Kevin Cashen, Ed Caffrey...

We buy something when it suits our fancy. A lot of time we end of with material for scales. :)
 
We are on the road, but there are a lot of makers we look forward to seeing. Billy Mace Imel, Kevin Cashen, Ed Caffrey...

We buy something when it suits our fancy. A lot of time we end of with material for scales. :)

Oh oh why did you give the wheels to Nathan? Unless you’re planning on getting there on time for Blade 2020? :p

Or has Nathan nicked the phone, answering as NinJo? :confused:

All kidding aside, have a blast y’all :)
 
Hi Nathan, what was your main takeaway(s) from this Blade 2019? Did your neurons go in overdrive with some new ideas? Were some of your own ideas complemented (as in bolstered) by your observations and feedback from others? Are you going to be moving some of the ideas on that white board of yours around, like moving something up the production pipeline and some in the back of the line.

Just in case you preferred to drink yourself silly during the socializing hours, don't be bashful to just admit to that :p
 
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