SK-5 failures? I seen some on Facebook...

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Nov 21, 2019
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There's CS nation group on Facebook and about a week or two ago there was around 3-4 broken SRK's and 1 Recon Tanto, all in SK-5.

Friend of mine recently had an issue with his SK5 Recon Tanto (the seller has replaced his knife).

Did you have any issues???
 
Where was the break at the tang? Tip? Don't do Fb and you are being quite vauge on the subject. Come on Man spit it out already, where's the break in the blade.
 
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There's more, but it took me plenty of scrolling to get to these as the group is very active (daily knife pic posts).
 
Sup Smiling. Been a while. Interesting breaks. Could be a bad heat treat. Or the user may have used the knife beyond reasonable limits. Did they supply the context as to how the knife broke?
 
Sup Smiling. Been a while. Interesting breaks. Could be a bad heat treat. Or the user may have used the knife beyond reasonable limits. Did they supply the context as to how the knife broke?
I've been really busy lately, and from tomorrow on it's starting again. Work and university directly after work, add few training sessions at week and a dog and wish to have social life on any day I can... and I don't have time for a thing...
 
I've been really busy lately, and from tomorrow on it's starting again. Work and university directly after work, add few training sessions at week and a dog and wish to have social life on any day I can... and I don't have time for a thing...
Good luck man. You got this.
 
sk5 is what Japanese made 1085 roughly, right? pretty tough steel if done right. I would think it would be hard to break outside of bad heat treat or really trying to break it. in to see more info on why........
 
You can break ANYTHING !

To have any meaning you've got to have context and trust the source of information .

Establish firstly that the product is actually genuine Cold Steel . Tons of counterfeits around and some are very hard to tell .

You have to know not only the immediate circumstances of the failure , but also the history of use/abuse . Damage can be cumulative .
 
You can break anything.
Yes this is true me and two other fellow worker roughnecks broke the handle off a pipe wrench in the oil field that was 5ft long with a cheater bar trying to tighten a big nut on the drilling rig. That pipe wrench must have weighed 40 or 50 pounds. So yeah just about anything can be broken especially a knife and like you mentioned it may also be a fake.
 
Let’s begin with the third photo (point damage). There is active rust there, so the knife was likely fractured for a while before the final failure.

n2s
 
sk5 is what Japanese made 1085 roughly, right? pretty tough steel if done right. I would think it would be hard to break outside of bad heat treat or really trying to break it. in to see more info on why........

SK5 (which stands for "Steel Kougu 5" - Tool steel #5) is indeed a Japanese carbon steel. Very similar to 1080, with carbon content close to 1085/1095. Maybe 10-15 years ago there was only Japanese made SK5. But it is currently manufactured by many Steel makers in Asia. Including China, India and Taiwan. To date I have never heard of any knife of any brand manufactured in Japan with SK5 having any steel quality issues. And I have seen them from 1986 onwards.
 
That grain structure looks like the steel was too hot when quenched, or not thermal cycled to refine/shrink the grain.

If the heat treat were right, I would not expect to see visible, large coarse grain like coarse sugar/sand.
 
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It us unlikely those are fake as the guys in that group are CS nuts, I've even see posts where they're spotting fakes online based on either upper swedge grind and angle on Spartan or one letter on the logo on other knives, even based on screws or bolts used... they do that shit just for fun.
And the dudes whose knives broke have bought them from reputable sources (CS site, physical store and Lamnia).
The guy with coarse grain was chopping bushes at below -10C when his knife snapped.
 
Here’s an insightful and scientific article from Larrin so we can shine a little more light on this matter.

https://knifesteelnerds.com/2018/12/21/why-cold-steel-is-brittle/

In brief, apparently cold temperatures can potentially lower a steel’s toughness. The article also suggested attributes which can help mitigate the reduction in toughness (reduction in carbon content, grain size, impurities, etc.).

I can’t comment first hand experience since we don’t have sub-zero temperatures over here. Conversely, heat is a huge pain in the ass during summer.
 
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