K390 ran softer in Golden PM2 & Para3 ???

[BeggarSo]

Recently I have become a big fan of K390. I have a Stretch2XL and 2 Delicas on SE the other PE. All hold a phenominal edge that is sticky sharp.

Recently I came across some questionable internet gossip that K390 in Golden models is not heat treated as hard as the models I have.

This has discouraged me from buying a PM2 or Para3.

Is there any truth in this? And if there is has anyone actually noticed a difference?

These knives are a bit over priced in my opinion but willing to buy, just dont want an expensive dissapointment.

I have experienced great steels ran too soft from other sources and it pretty much ruins them.

[Brock O Lee]

Is there any truth in this? And if there is has anyone actually noticed a difference?

Yes, this is true. If I remember correctly, Outpost76 on YT did a few comparison tests.

I do not have personal experience with the Golden K390's, but from what I've read was that they were heat treated a few points softer than the Japanese models. Whether most people would notice a performance difference in day-to-day use is debatable.

Edit: here is a comparison cut test between the two, with HRC measurements.

PM2 (USA) K390 - around 63.5 HRC
Police 4 (Japan) K390 - 65.5 HRC

[srivats]

Is there any truth in this? And if there is has anyone actually noticed a difference?

Yes, this is true. If I remember correctly, Outpost76 on YT did a few comparison tests.

I do not have personal experience with the Golden K390's, but from what I've read was that they were heat treated a few points softer than the Japanese models. Whether most people would notice a performance difference in day-to-day use is debatable.

Edit: here is a comparison cut test between the two, with HRC measurements.

PM2 (USA) K390 - around 63.5 HRC
Police 4 (Japan) K390 - 65.5 HRC

Sample size of 1 knife from each location, so it's difficult for me to believe every knife is this way without statistics to support it. I wouldn't put much thought into this rumor.

[RustyIron]

internet gossip that K390 in Golden models is not heat treated as hard

Usually I dismiss "internet gossip" unless I know the source. There are a lot of donkeys out there braying for attention. But let's be open minded. Were their contentions supported with data? Did the donkey have a hardness tester? What were the results? Were the results within the deviation one might expect?

Further, is it BAD to have a blade that is not as hard as the type of steel allows? I can imagine that maximizing hardness might diminish other desirable qualities of the material. Perhaps Spyderco is heat treating its blades exactly as Sal intended.

The bottom line is, I don't know. But I'm certainly not going to get all wobbly in the knees and avoid using a knife that I thought was good before reading a random internet post.

[Danke]

If you go on the Gram with a knife that doesn't have as many Rockwells as theoretically possible you'll be laughed out the front door.

The HRC Mafia knows that's the only number that matters when garnering likes.

[Red Leader]

I've also heard that Seki may run their Cruwear (ala Stretch 2 XL) harder than Golden...I think Gabe at the Home Slice may have been talking about this, or perhaps it was a part of the discussion in the comments of one of his videos.

It would be great to get some more test results between Golden/Seki K390, and Golden/Seki Cruwear, just to have the data so folks can make informed decisions.

[Skywalker]

I've also heard that Seki may run their Cruwear (ala Stretch 2 XL) harder than Golden...I think Gabe at the Home Slice may have been talking about this, or perhaps it was a part of the discussion in the comments of one of his videos.

It would be great to get some more test results between Golden/Seki K390, and Golden/Seki Cruwear, just to have the data so folks can make informed decisions.

I would be surprised if Seki is running Cruwear significantly harder than Golden since Golden seems to be running it 61-63, based on this thread: viewtopic.php?t=83847

Not much non-coated Cruwear/PD#1 coming out of Seki though, right? Might complicate hardness testing if there's fewer satin options to test.

[dsvirsky]

But does it really make for an informed decision? Harder is just that, harder. Not necessarily a more suitable heat treat and not necessarily better performing at any metric.

[Ramonade]

PM2 and Para 3 were the first with the steel, my guess is that a new protocol has been established thanks to these first runs. Giving Seki the perfect one to apply on their production.

I did not notice much difference in use between my PM2 and the rest, but it is impossible to tell because all of my K390 knives from Seki have a way slicier cutting geometry than the PM2.

[ekastanis]

I believe the first two knives with K390 were the MT and the Police 4 G10

[Midnightrider]

Does it really matter? I'm sure whatever got sold met Sal's requirements both as to HRC and quality of heat treat.

I think @ekastanis is probably right about the P4 being one of the first but I can't remember that far back for sure.

[Brock O Lee]

Yes, this is true. If I remember correctly, Outpost76 on YT did a few comparison tests.

Sample size of 1 knife from each location, so it's difficult for me to believe every knife is this way without statistics to support it. I wouldn't put much thought into this rumor.

Yup sample size of one. However in the video he mentioned other hardness results (one by Shawn Houston) which aligned with 63.5 HRC. So perhaps sample size in the single digits...

Of course, it would have been better to have results for a statistically significant cohort, but we don't have that. Take this result at face value IMO, or provide evidence to the contrary.

The wear resistance of these knives are so high, personally I don't think most people would notice a difference.

[Red Leader]

But does it really make for an informed decision? Harder is just that, harder. Not necessarily a more suitable heat treat and not necessarily better performing at any metric.

I mean if you know, wouldn't that mean that you are more informed? It sounds exactly like what the OP is trying to know so they can decide if they want to buy the knife. Of course, there is an inference that K390 that is run harder will have better edge wear resistance - which to me seems like a reasonable expectation. The 'not necessarily' is why we are wanting more hardness numbers and any cut test results on these knives; I'd like to know myself. The relative performance of Seki K390 has been fairly well documented, along with accompanying hardness test numbers across several examples, whereas the Golden K390, far less so.

[BeggarSo]

Yes, this is true. If I remember correctly, Outpost76 on YT did a few comparison tests.

Sample size of 1 knife from each location, so it's difficult for me to believe every knife is this way without statistics to support it. I wouldn't put much thought into this rumor.

Yup sample size of one. However in the video he mentioned other hardness results (one by Shawn Houston) which aligned with 63.5 HRC. So perhaps sample size in the single digits...

Of course, it would have been better to have results for a statistically significant cohort, but we don't have that. Take this result at face value IMO, or provide evidence to the contrary.

The wear resistance of these knives are so high, personally I don't think most people would notice a difference.

Thanks you got the spirit of my post and put in better words.

Heat treat makes a difference this is not a myth, and when potentially spending hundreds of more dollars I expect the Golden steel to be just as good as Seiki, for those prices it better be.

So more information is always welcome, if only some cut tests Seiki Stretch versus PM2 perhaps. Too bad they both dont make the same models.

[srivats]

Yup sample size of one. However in the video he mentioned other hardness results (one by Shawn Houston) which aligned with 63.5 HRC. So perhaps sample size in the single digits...

Of course, it would have been better to have results for a statistically significant cohort, but we don't have that. Take this result at face value IMO, or provide evidence to the contrary.

The wear resistance of these knives are so high, personally I don't think most people would notice a difference.

Folks that have spent time in manufacturing understand the standard bell curve you see for variation :) I am going trust Sal and Spyderco that when they put out a k390 blade, it's to their spec no matter where the knife is made and it's well within what they consider acceptable.

Your last sentence is absolutely the only one to keep in mind, well written.

[Doc Dan]

Run

[Evil D]

I'd just like to go on record and say I still want a K390 Bodacious.

[BeggarSo]

Well I wouldn't turn my nose up to a K390 Manix XL that's for sure.

[blueblur]

I’d like to see some American models in SE K390.

I’m also very curious what the Yojimbo would be like in SE.

[dan31]

Still waiting for a Native 5 in K390. Seems obvious, but then again they are busy.