Is SK-5 Recon Tanto hardened at 65HRC?

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Smiling

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So, today I went to the forrest with a friend of mine who recently bought Esee-5.

We tested and compared our knives.

Anyways Recon Tanto was a way better chopper which is to be expected because the knife itself is bigger.

We didn't test tip sthrenght since he himself said that he knows tanto is better for that.

Anyways most shocking discovery for both of us was that Recon Tanto had significantly better edge retention than the Esee 5 which is made out of 1095 steel. Significantly meaning several times better.
So SK-5 is basically 1080, and 1095 should be superior when it comes to edge retention.

Now the guy texts me that he found out that Recon Tanto is hardened at 65HRC which is crazy. I tried looking it up and several pages say the same thing. This would explain the difference, but wouldn't the blade be very brittle then? I mean I beat the hell out of it and I never had a chip or anything.

Any reliable source on it's hardness?
 
I just checked the website.
That is the "As Quenched" hardness.
Which means before tempering.

They are likely running the blade around 58-60HRC after a couple tempering cycles. But it is a tough steel and could definitely be 61HRC as well. This would explain the toughness and increased edge holding. It's an easy steel to heat treat. Cold steel likely hardened it to balance toughness and edge holding.

In the mean time, enjoy the knife!
 
ShannonSteelLabs said:
I just checked the website.
That is the "As Quenched" hardness.
Which means before tempering.

They are likely running the blade around 58-60HRC after a couple tempering cycles. But it is a tough steel and could definitely be 61HRC as well. This would explain the toughness and increased edge holding. It's an easy steel to heat treat. Cold steel likely hardened it to balance toughness and edge holding.

In the mean time, enjoy the knife!
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Thank you for your detailed answer.

Now this explains a lot, since Esee5 appears to have lower HRC.
 
D17A1 said:
Did you happen to test the ease of sharpening each knife?
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In a matter of fact - we did.
About same time if we don't count extra time I spent on secondary edge of my tanto tip, sharpened on the same stone, but each person was sharpening their own knife so it could vary because of human factor.
 
Smiling said:
So, today I went to the forrest with a friend of mine who recently bought Esee-5.

We tested and compared our knives.

Anyways Recon Tanto was a way better chopper which is to be expected because the knife itself is bigger.

We didn't test tip sthrenght since he himself said that he knows tanto is better for that.

Anyways most shocking discovery for both of us was that Recon Tanto had significantly better edge retention than the Esee 5 which is made out of 1095 steel. Significantly meaning several times better.
So SK-5 is basically 1080, and 1095 should be superior when it comes to edge retention.

Now the guy texts me that he found out that Recon Tanto is hardened at 65HRC which is crazy. I tried looking it up and several pages say the same thing. This would explain the difference, but wouldn't the blade be very brittle then? I mean I beat the hell out of it and I never had a chip or anything.

Any reliable source on it's hardness?
Click to expand...

65 HRC would be the "as quenched" hardness, before tempering. The final tempered hardness would be somewhere between 55 and 60.

Edge retention is a function of shape, not just alloy and hardness. So it's hard to compare two different blade shapes and draw conclusions about the edge retention of the alloy itself.
 
knarfeng said:
65 HRC would be the "as quenched" hardness, before tempering. The final tempered hardness would be somewhere between 55 and 60.

Edge retention is a function of shape, not just alloy and hardness. So it's hard to compare two different blade shapes and draw conclusions about the edge retention of the alloy itself.
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I get that. But I think that heat treatment plays a role here too.
Esee 5 is apparently heat treated at 55-57 HRC, so if Recon Tanto is at 60HRC it'll make a big difference.
 
The closest I have found for information is a non-BF dealer site which sells the Cold Steel SRK, which is also in SK-5
The blurb for that one says that the blade has an "RC Hardness of 56-57"
It's a fair assumption that both knives are made in the same shop to the same hardness spec.

56-57 passes my filters for a "hard use survival" blade. 60 is likely to break at an inopportune moment in such usage.
 
Well I hit a lot of hard things with my Recon Tanto using lots of force and I never had issues. I don't know what it's hardness is, but I'm very curious about it because both, me and my friend are curious to know reasons why is edge retention so much different in unlikley way.

Since SK-5 is essentially 1080, and Esee 5 is made out of 1095 which should hold the edge better and for some reason it doesn't. Secondary bevel on our knives is very similar in shape and angle, biggest difference being the fact Recon Tanto has hollow grind while Esee 5 is saber grind, and last difference being the fact the Esee 5 has thicker blade.

In my personal opinion heat treatment is most likley the cause.

If my knives in 52100 or D2 were to outperform 1095 the way SK-5 did I most likley wouldn't even make the thread about it.
He also seems to be very displeased by edge holding of his Esee 5.
 
Even a big brand like ESEE may screw up a heat treat batch every now and then. Or maybe he got a fake.

If you get a chance, compare both with some more knives so you can get an idea of whether the Esee is underperforming or the Recon Tanto is actually punching above its paygrade...
 
bemymonkey said:
Even a big brand like ESEE may screw up a heat treat batch every now and then. Or maybe he got a fake.

If you get a chance, compare both with some more knives so you can get an idea of whether the Esee is underperforming or the Recon Tanto is actually punching above its paygrade...
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I asked him about it, he bought it through reputable site.

He wasn't very happy about it which is one of the reasons why he reprofiled the secondary bevel. He also thought that steel might be "burnt" so removing the material will help bringing out good steel.
Despite reprofiling, edge retention was first outperformed by Mora, which has a much thinner blade, afterwards he asked me to take my Recon Tanto and go to forrest with him and test the performance toe to toe with him, since Recon Tanto has similar blade thickness to Esee 5.

He currently considers returning the knife (14 days rule after online purchase) and getting a refund. Biggest blow to him was the fact that Recon Tanto costs around 30% of the price he paid for Esee 5.

My personal opinion about this is that he most likley got a "lemon"...
 
Smiling said:
I asked him about it, he bought it through reputable site.

He wasn't very happy about it which is one of the reasons why he reprofiled the secondary bevel. He also thought that steel might be "burnt" so removing the material will help bringing out good steel.
Despite reprofiling, edge retention was first outperformed by Mora, which has a much thinner blade, afterwards he asked me to take my Recon Tanto and go to forrest with him and test the performance toe to toe with him, since Recon Tanto has similar blade thickness to Esee 5.

He currently considers returning the knife (14 days rule after online purchase) and getting a refund. Biggest blow to him was the fact that Recon Tanto costs around 30% of the price he paid for Esee 5.

My personal opinion about this is that he most likley got a "lemon"...
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How good of a sharpening job did he do?
 
OrangeBlueOrangeBlue said:
How good of a sharpening job did he do?
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I can't say, he usually cuts paper for test, I personally shave my arm hair to test sharpness.

But I did handle his knife a bit myself, it was sharp to the touch at first, and it didn't take much before he gave me the knife again to see for myself - I could run my finger across the blade without much fear of getting cut.

We were mostly chopping at first, while the sharpening stone was resting in the water for later. Recon Tanto was a better chopper, and it held it's edge well.

Then we ate sandwiches.

He resharpened his Esee 5 to cut some rope, I just used 3cm of the blade which are closest to the handle to cut the rope (that part wasn't dulled at all during the chopping), he used around 3cm of his blade too. Recon Tanto outperformed it again, then he went to carving until the entire blade was dull again.
It took us roughly same ammount of time to resharpen, if we don't count additional time I needed for tanto tip. But I didn't really use stopwatch or anything to measure the time, I'm just saying approximatley.
 
I'm not sure I'd trust someone who said a mass produced SK5 survival knife was hardened to 65 HRC...
 
Yeah 65 HRC for that knife as a finished product after tempering just sounds wrong.
Somewhere between 55-60 sounds about right.
The only functional knives I've seen that hard after tempering are made with steels that have more alloying elements than a basic carbon steel (ZDP-189, HAP-40)
and even those steels can be a bit chippy at the edge where as I'd expect a steel like SK-5 to pretty much snap in half if used hard at that HRC.

SK-5 is a great steel for applications where toughness is a bit more desirable than edge retention, but the edge retention should be respectable as well.
In other words, I don't mean to poo on SK-5, it's just that an HRC of 65 would negate it's positive qualities, in my opinion.
 
Korean Hog said:
I didn't catch that at first, but yeah if you plan to return the knife after using and sharpening....that is NOT cool o_O
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It's not my knife.
And I told him the same thing.
craytab said:
I'm not sure I'd trust someone who said a mass produced SK5 survival knife was hardened to 65 HRC...
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Yeah, I made this thread for that reason. I couldn't believe it.

If you google "Recon Tanto SK5 65HRC" you'll find at least 3 large webshops which actually have 65HRC put there as the blade hardness.

But, since that same information isn't on Cold Steel website I took it with grain of salt.
I also wrote on my original post that it is crazy because then it'd be very brittle.

I'm interested to know why this SK-5 holds an edge better than 1095 when it should be other way around. My guess is that hardness is culprit. If his Esee is tempered at 55HRC and Recon Tanto is at for example 57 or 58 - that alone could explain the difference.
 
Smiling said:
I'm interested to know why this SK-5 holds an edge better than 1095 when it should be other way around. My guess is that hardness is culprit. If his Esee is tempered at 55HRC and Recon Tanto is at for example 57 or 58 - that alone could explain the difference.
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In your one instance of unscientific testing with completely different knives in different steels from different companies you found a difference. Let's not blow this out of proportion. I'd say there are too many other things going on to narrow it down to the steel (grind and thickness being a big factor). Further, I'd worry about trusting the experiences of anyone that thinks that SK5 was at 65 HRC. What else are they getting wrong here?
 
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