K390 vs... K390?

[Albatross]

I am interested in finding out what kind of performance differences some of you might have noticed, between the P4 G10 and the PM2/Para 3 K390 exclusives. I've seen testing that shows lower hrc numbers on the U.S. models, which has made me curious. If you have experience with the P4 and PM2/Para 3, I would love to know what real use has revealed.

Do they sharpen similarly? How does the edge stability compare between the models? Does one react more to corrosion or are they similar?

[SpyderPhreak]

I can't comment on the non-US models yet unfortunately.

I can tell you that my PM2 took a pretty heavy patina, second only to 52100 in my experience, and quite a bit more than REX45. That surprised me a little; I was expecting it to patina a bit more than REX45, but not this much more. To be clear, I'm OK with it, but it's of note and was a bit surprising. I haven't needed to sharpen mine yet, but the factory edge has held up impressively well so far, even deburring small bits of 7075-T6 Aluminum on the wind tunnel model I'm currently testing.

K390 Patina:

Other PM2s for reference:

52100

Rex45, M4, Maxamet

I can try to get good pics of all 5 knives together next week, to show the comparative level of patina in the same photo.

[Albatross]

I can't comment on the non-US models yet unfortunately.

I can tell you that my PM2 took a pretty heavy patina, second only to 52100 in my experience, and quite a bit more than REX45. That surprised me a little; I was expecting it to patina a bit more than REX45, but not this much more. To be clear, I'm OK with it, but it's of note and was a bit surprising. I haven't needed to sharpen mine yet, but the factory edge has held up impressively well so far, even deburring small bits of 7075-T6 Aluminum on the wind tunnel model I'm currently testing.

K390 Patina:

IMG_5025.jpg

IMG_5024.jpg

7868819C-C830-4738-91B4-FE45469DCC62.jpeg

8C5D7C21-6EB9-43D4-A2A4-9F132CABEB78.jpeg

08DB30B5-143F-476A-93FB-AC942F9660D1.jpeg

Other PM2s for reference:

52100
IMG_4575.jpg

Rex45, M4, Maxamet
IMG_6879sm.jpg

IMG_6877sm.jpg

IMG_6878sm.JPG

I can try to get good pics of all 5 knives together next week, to show the comparative level of patina in the same photo.

Nice set of users!

I wondered if it might patina faster. My P4 K390 was slower to develop a patina than my Rex knives. I'm not sure if that's an anomaly, or the norm.

Thanks for sharing and hopefully you get the opportunity to try a Seki-made K390 knife, especially if it's heat treated the same as the P4.

[JMM]

I can say that I had the bright idea to force a patina on my P4 k390, and I didn't like the way it turned out, on my Para3 k390 I just give it a VERY light wipe-down with Mineral oil and it seems very happy, I had my Para3 Rex45 given a dark acid-wash finish by Franky-Blades and I love the way it looks, I left my PM2 Rex45 alone (other than a light wipe-down with mineral oil) and I've only had one small spot on the blade that bar-keepers-friend took care of in about 10 seconds... as far as sharpening k390, I'm not awesome at it, but I'm ok, I can do Rex45 better than anything but superblue, and it is only marginally more difficult than s30v, I think edge holding is nearly identical between k390 and rex45, although that may be because I'm a bit better at Rex45 from more practice... either way though, both are amazing steels, half of my fave-four .... Rex45, 4V, K390, Cruwear

[Mattysc42]

Huh, mine has barely patinad at all, even when soaking in my sweat at work. It has a bit of a gold and blue patina near the edge from cutting strawberries, too mild to get a picture of, but that’s it. It’s nice to have non-battery acid sweat :p

[JonLeBlanc]

I just yesterday found some rust on the ricasso of my Police 4. It's a semicircle so I reckon there was some moisture under the liners around the pivot. I haven't dealt with it yet, but I'm sure it'll come right off with the appropriate treatment, so it doesn't bother me. I like non stainless steels anyway, so for me it's a small price to pay. But it is an interesting question how the same steel would react given the variation in heat treat that may obtain between the Seki City and Golden models. Makes me wish I had one of those Paras to compare the two!

[TomAiello]

I realize you didn't ask about Maniago, but..

My gut feeling is that the P4 K390 is run harder than the Urban K390. I don't the Para 2 or Para 3 in K390 to compare to though. Edge stability seems to be about the same (hard to say in such different knives) but the Urban seems to sharpen up quicker/easier than the P4, for me. That's unusual for me because I usually find larger blades easier to sharpen, which is kind of why I noticed it in this case.

[Albatross]

This is all very good info... I might have to get a K390 PM2... for science. :D

[Pancake]

From some tests, K390 from Golden is like 1 HRC lower then on Police 4.....I think you will be very hard-pressed to see a difference in real life. If you would a controlled cut test, then maybe yes, but not that much in real life.