CRK steel hardness question

[joeyza]

On my Umnumzaan birth certificate it says "S35VN - 58-59 RC".
I was just wondering, since it mentiones the specific hardness for each knife, do some CR knives have different hardness levels then others? For example, could someone out there have an umnzaan with a hardness level higher or lower than mine? Is the hardness level on each birth certificate specific to that exact knife or is it just a general range of hardness for all CRK's?

 

[HwangJino]

I would love if crk did offer different hardness.

I like hardness around 56 for outdoors and higher for slicing.

 

[au5t3n5]

They try to do it all the same. There is a reason CRK wins manufacturer of the year almost annually, and I would consider consistent heat treat to be a part of that.

That said, I think there have been a few duds, and different batches have slightly different RC ratings (thus 58-59 instead of a solid number), but its more or less all the same - they don't do batches of like 58-59 RC blades and another batch of 60-61 RC blades for the same knife, they try to heat treat the blades the same based on the steel they are using. I think they took other steels like BG42 to a higher RC.

CRk tries to heat treat all their knives the same

 

[benthughes]

I've owned several of the Reeve one piece knives as well as a couple of the Pacifics, one in S30V and one in S35VN. The hardness on all the cards was 55-57RC. All the Folders I've seen have been 58-59RC on both the S30V and S35VN knives. I believe that it's a general range but a couple blades in each batch are hardness tested for quality control. I've heard that theres a generally imperceptible difference in 2 points of RC hardness, as a knifemaker you probably know better than me. There was a thread I came across where the actual rockwell hardness was tested vs. advertised values for many popular knives.

I'm sure someone far more knowledgable will come along and offer something more valuable than my limited experience.

 

[Ernie1980]

Here's the test that was run, I found it interesting but would love to see more knives tested!!

http://www.bladeforums.com/forums/s...of-a-sampling-of-production-and-custom-knives