Ranking of Steels in Categories based on Edge Retention cutting 5/8" rope

djdawg said:
Isnt that harder than Chris Reeve does his Sebenzas ??
Thats the only thing Ive read on Sebys knives is the blades were suppose to be too soft.
Is there any truth to this statement ?
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Not from what I have experienced, my CRK Zaan in S30V tested at 59.5 RC.
 
He is Fantoni. From Italy.
I won't comment any longer the ht path that CRK adopted.
I simply made up my mind not to buy from them any longer. Period.
 
I sure like the build of them ............. alot
I only sold because I heard various bad things about edge holding if this knife.
I should probably rethink it.
 
I think a lot of that had to do with people running super duper acute edge angles. CRK's are not going to have extremely high wear resistance - but that is definitely by design IMO.
 
Ankerson said:
Same here, it's been positive for me also. :thumbup:
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It USED to be positive for me as well until BG42 (top notch HTd BTW) was phased out.

What follows it is well known to you, but maybe introducing the whole picture to our buddies might be helpful.

Not limiting to CRK, and I'm sure you'll will part with me to this extent, steels like S30V, S35VN, Elmax, M390 (and its clones) all share 14% or more CR, 1.4% of C, 3% or more of V and S35VN has also Nb.
As I've said many times in this thread if one of these steels is below 60.5 for the CPM grades and 61 for the Bohler fellows the very direct consequence is edge instability. Try to get a Sebbie to 30° included straight (i.e. NOT convex) edge to see what I mean.
But from hardness and steels datasheets you can get an idea of many other factors.
We'd just like to have these steels decently stainless, would not we? Well, sorry folks but to reach >60HRC with these buddies requires high austenitizing temps, 5bar gas overpressure quenching and eventually cryo (to minimize retained austenite) in between low temp tempers. This in a production HT path.
What happens if HRC is <60 ? Given what above the austenitizing temps will be done at temperatures that, due to CR and C content will generate some Cr7C3 carbides AND Cr23C6 carbides. The latest will take away far more Cr from the amount that could be otherwise available to stain resistance extents AND with Cr23C6 carbides we'll have intergranular corrosion issues. So much carbides means less C available in solid solution to ensure hardness and thus edge stability.

That's not all. V, Nb (and W as well, which is in M390) do actually need higher temps in order to properly solute in the austenitic matrix, hence another reason to use austenitizing temps in excess of 1120°C for mentioned steels. The more you raise aust. temp the more you COULD face grain growth, thus the reason for using an overpressure quenching. But please bear in mind that V, Nb, and also W actually help minimizing this risk (even as low as a 0.20% V content will be quite effective).

Bottom line: mentioning that hardness is kept down to ensure toughness (in a folder) is PLAIN NONSENSE, given the meant use for a folder of this class (or a folder altogether). A folder is not a prybar, a hatchet, a machete....BUT, should more toughness be required, the answer it is NOT in underhardening an improper steel, it is choosing another steel like CPM-3V, which @59 delivers a very good edge stability/toughness combination ;)
 
daberti said:
. Try to get a Sebbie to 30° included straight (i.e. NOT convex) edge to see what I mean.
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You mean like this one?

DSC_5307.JPG
 
daberti said:
It USED to be positive for me as well until BG42 (top notch HTd BTW) was phased out.
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Sounds typical of many company's. Once their name is made through quality workmanship, they start cutting corners in the name of more profit. :(
 
I don't know what the specs are for my S35V CRK's but I have them at about 30 Deg. and have been pleased with their performance. I just sharpened a Sebenza and cut a bunch of Bamboo and had no edge issues whatsoever. It was push cutting - but, still would have expected more edge loss.

I honestly don't think CRK is cutting corners. I think their business and sales have grown so much - if anything - they are trying to keep up with the growth.
 
skwurll said:
I don't know what the specs are for my S35V CRK's but I have them at about 30 Deg. and have been pleased with their performance. I just sharpened a Sebenza and cut a bunch of Bamboo and had no edge issues whatsoever. It was push cutting - but, still would have expected more edge loss.

I honestly don't think CRK is cutting corners. I think their business and sales have grown so much - if anything - they are trying to keep up with the growth.
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I am very pleased with my Sebenza 25 and the performance of the S35VN. :)
 
That's the point! My mileage with these steels in production knives realm it is not properly satisfying.
I can actually feel when hand sharpening with my Chosera stones what to expect from a blade.
 
Ankerson said:
I am very pleased with my Sebenza 25 and the performance of the S35VN. :)
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I wonder (just a curiosity) if you had ever a chance to do a side by side comparison with a Fantoni knife.
More could be said about the selling price of CRK here in Italy. A custom M390 folder from a RENOWN SA maker included shipping and VAT and various duties had been paid well less by myself.
Once again and back to the route: high Cr C, V steels do need a certain ht. This is due to physical requirements peculiar to alloying elements.
There is a "window" that allows for some adjustments towards toughness or edge stability. But I simply cannot tolerate any longer hearing from production makers that they stay three full Hrc points behind just to allow for more toughness or ease of sharpening.
I can actually bring the edge back on m390 @>62 just with few passes on Cr strop. Ceramic stick if more dull.
Same for s30v or alike.
I really cannot understand the metallurgical reasoning behind that HT.
So, same maker same knife one blade in Elmax at 59 and another in Aeb-l +304l Damascus at 61 I went with the latter.
 
I really like the 25's Ankerson. I had to pick up a second one.

I wouldn't compare CRK's to custom knives or refined custom treating though daberti.

You guys know much more about Metallurgy than myself I'm still learning and have a lot to learn.
 
I know nothing and have everything to learn ......... I judge my choice of steels on others post and reviews , not real world use.
I use my knives "yes" but not everyday and not enough to really be a judge.
Hell , I think Elmax has held up really well in my cardboard box cutting up routine.
 
Mate, I'm still learning as well!!
I didn't compare a custom vs a production. I had been forcibly put into the attitude of thinking that a folder with a superior and custom ht and fit and finish would have costed me 25% less than a certainly inferior production knife. Obviously enough I got the custom.
 
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