They're everywhere!

[Albatross]

Now that the market has been flooded with Rex45, and with K390 being released in several more models, (with more to come) what are your thoughts on these steels? I've seen quite a few comments about how great each is, but that's it. No reasons, just that they're impressive steels. I can't argue that, but my ego wants bias confirmation.

What do you use knives with those steels for (work, edc, or?) and have they replaced other steels in your arsenal or were these steels just not for you? Have they performed beyond your expectations? Were they your introduction to exotic blade steels? What do you think about how they sharpen? Do the edge characteristics make these steels more interesting to you? Any and all input on these steels would be great, and might help some others make a decision about whether or not to buy a knife with Rex45 or K390 blade steel.

I've shared my thoughts on both steels in a few threads here, so I'll leave it up to any of you who recently found these steels. I'm sure some of you are tired of me talking about these steels. :D

Wartstein, I'll be interested in seeing what you think of your new Manix, now and after some more use. Your experience with Hap40 makes your input quite valuable, as one of the few users who has/will extensively cut with both steels.

[Wartstein]

....

Wartstein, I'll be interested in seeing what you think of your new Manix, now and after some more use. Your experience with Hap40 makes your input quite valuable, as one of the few users who has/will extensively cut with both steels.

Thanks for thinking of me in that context!

I´ll do my best to give my input and a comparison since I have indeed used HAP 40 a lot and in many different tasks and certainly will do so with my REX 45 Manix LW (I´ve already started, see here https://forum.spyderco.com/viewtopic.ph ... 0#p1455172)

But keep in mind: I have not the knowledge about steels like you and many others here, and my impressions are just this and totally anecdotal..

[TkoK83Spy]

My thoughts are in here on Rex45, as well as a few others...

https://forum.spyderco.com/viewtopic.php?f=2&t=86207

[Albatross]

My thoughts are in here on Rex45, as well as a few others...

https://forum.spyderco.com/viewtopic.php?f=2&t=86207

Thank you for linking that thread.

[Menipo]

Thanks Albatross for opening this thread!!!

I have said in other posts/threads that I am not particularly fond of steels "with an inclination to rust". This applies to K390 in particular after I watched the following video: :eek: :eek: :eek:

https://youtu.be/UGfPTbwxwUI

But I have seen so many Forumites here excited about getting (or begging for) new releases with that steel, that I was wondering what K390 offers to turn the corrosion problem into a minor disadvantage. :confused:

So I am anxious to get the secret revealed! :D

[vivi]

September 8th I put a fresh edge on my K390 Police.

I got it shaving sharp off a 300 grit diamond plate, then stropped a bit. Checking the edge today, the 23rd, that coarse, toothy edge still easily shaves. Over two weeks later and I can't detect a difference.


I have gone out of my way to use it since then. Cutting food, making feathersticks, sparking ferro rods, slicing up cardboard and old credit cards, cutting rope, opening mail, opening packages, slicing pallet straps etc.

Granted most of this is easy work for a Police, but the fact it feels just as sharp as when I put the edge on it is impressive.

I've never seen any chips or rolls, so it seems plenty tough.

Corrosion has not been an issue for the blade. The liners on my Police show a lot more corrosion. Kind of confused by that. Hoping if I buy the lightweight K390 police the liners are more corrosion resistant.

I'd like to see a small fixed blade in this steel, like a Street Beat or enuff.

[Albatross]

....

Wartstein, I'll be interested in seeing what you think of your new Manix, now and after some more use. Your experience with Hap40 makes your input quite valuable, as one of the few users who has/will extensively cut with both steels.

Thanks for thinking of me in that context!

I´ll do my best to give my input and a comparison since I have indeed used HAP 40 a lot and in many different tasks and certainly will do so with my REX 45 Manix LW (I´ve already started, see here https://forum.spyderco.com/viewtopic.ph ... 0#p1455172)

But keep in mind: I have not the knowledge about steels like you and many others here, and my impressions are just this and totally anecdotal..

Thanks for sharing. It looks like you and that knife will be spending a fair bit of time together!

That's okay, you don't need to have knowledge of steel composition or any of the technical stuff, to see how the two steels perform. Most of us are providing anecdotes, but it's still important feedback, because Catra doesn't always accurately show the kinds of results people see with real use. See Spy27 anecdotes for reference.

[Mattysc42]

Rex45 and K390 are the most stable steels of any I’ve used so far. Light impacts or slicing cuts against hard surfaces rarely cause any chipping, rolling, or loss of sharpness in these steel in my experience. K390 in particular is also exceptionally wear resistant and will easily maintain sharpness through a full day’s work for me, even when cutting several hundred feet of exceptionally abrasive industrial cardboard and dozens of heavy duty pallet straps.

I’ve never found a reason to care about corrosion on blades, though I use a combination of tuff-glide and smooth-kote on the pivot and tang area in my folders.

K390, 10v, and Rex45 are by far my favorite non-stainless steels, followed by Maxamet.

[aicolainen]

I mostly use my knife in outdoor related activities, so I have a natural bias towards the stainless options.
To spice up my knife drawer with some handle color and steel variation, I got my Lil'Native in REX 45. Not being stainless didn't matter much for that particular knife, and it's interesting to widen my horizon and try different steels.

Now I might be wrong, but I don't really think that a Lil'Native is the optimal platform to experience the advantages of REX 45.

So let's say I wanted to test K390 somewhere down the line (in a distant future) when a spot opens up in my knives-to-acquire list. What would be a really good choice of knife to get the most out of that steel?

[Baron Mind]

In a nutshell, compared to the 59-60 hrc stainless steels used in most midrange production folders, rex45 and k390 offer noticeable increases in wear resistance and edge stability. Their edges don't dull as fast, and don't roll as easily. The tradeoff is they can rust if neglected.

[TomAiello]

So let's say I wanted to test K390 somewhere down the line (in a distant future) when a spot opens up in my knives-to-acquire list. What would be a really good choice of knife to get the most out of that steel?

Police 4. Plenty of blade to experience, and the steel really shines in a larger, 'hard use' folder. In a smaller blade I'd rather have something like Maxamet (or s110v).

[bdblue]

They are my new 2 favorite steels. I have a Manix 2 LW Rex45 that I use for working around the house, and a PM2 K390 that is my favorite EDC. Previously I had several knives in M4 that I carried, I don't think that it is a big jump from M4 to Rex45 or K390.

[JohnDoe99]

REX 45 corrodes very easily, almost like Super Blue. It is among the hardest steels I've used and sharpens surprisingly easily, but honestly I am wanting a stainless back. I just don't feel like the constant maintenance warrants the marginal practical advantage in edge performance.

[JuPaul]

I mostly use my knife in outdoor related activities, so I have a natural bias towards the stainless options.
To spice up my knife drawer with some handle color and steel variation, I got my Lil'Native in REX 45. Not being stainless didn't matter much for that particular knife, and it's interesting to widen my horizon and try different steels.

Now I might be wrong, but I don't really think that a Lil'Native is the optimal platform to experience the advantages of REX 45.

So let's say I wanted to test K390 somewhere down the line (in a distant future) when a spot opens up in my knives-to-acquire list. What would be a really good choice of knife to get the most out of that steel?

Well your choices for a larger k390 knife are either a PM2 (for sale at BBS), or the Police 4 lightweight or Endela/Endura models coming out really soon. Any would be a great option depending on your size and lock preference. But, I also have a feeling that we're going to see a Shaman in k390 sometime soon, and that's an excellent beefy outdoors knife, imo. It sounds like you don't mind waiting, and a k390 Shaman would be well worth waiting for.

[aicolainen]

@TomAiello & @JuPaul, thanks for your input.

I've never had the opportunity to handle a Shaman, but I have no doubt it's really good. Still my intuition tells me that I would usually prefer a fixed blade for the tasks where the Shaman really shines. Hard use and folding knives is not compatible i my head, it doesn't matter if there exist evidence to suggest otherwise. That's just the way it is.
A long bladed, reasonably light weight folder, like the P4LW is something I could actually see a slight potential in, even for my typical use cases. And I must admit that the K390 Police 4 LW in reveal 6 caught my eye.
So even if I don't see an obvious need for a folder of that size, knowing that it's actually a good platform for K390, I think that when budget allows, it could be worth having a folder with a really long blade just for the fun of it.

[Albatross]

@TomAiello & @JuPaul, thanks for your input.

I've never had the opportunity to handle a Shaman, but I have no doubt it's really good. Still my intuition tells me that I would usually prefer a fixed blade for the tasks where the Shaman really shines. Hard use and folding knives is not compatible i my head, it doesn't matter if there exist evidence to suggest otherwise. That's just the way it is.
A long bladed, reasonably light weight folder, like the P4LW is something I could actually see a slight potential in, even for my typical use cases. And I must admit that the K390 Police 4 LW in reveal 6 caught my eye.
So even if I don't see an obvious need for a folder of that size, knowing that it's actually a good platform for K390, I think that when budget allows, it could be worth having a folder with a really long blade just for the fun of it.

The P4 is a good choice and I think the size will become less of a thought over time. I've used my P4 for just everything and it has never left me wanting a smaller knife.

[aicolainen]

it has never left me wanting a smaller knife.

I think the constraints regarding size exist mostly in my head :)
My mental constraints tell me that the ideal use case for a folder is something that takes advantage of it's small footprint, this advantage becomes less obvious to me when I have to carry around a lot of unused handle area. Take into account that I have quite narrow hands, that line is crossed quite early.
That said, when the the blade gets long enough, I again start to see how a folder could be an advantageous platform. My fixed blades are typically small to mid sized because that's the ideal size for what I mostly use them for, but ever so rarely those edges doesn't quite cut it when the matter to be separated exceeds a certain size, and I think a long bladed folder would be a perfect companion knife to my fixed blades in certain situations. Even though the handle provides much more grip area than I could practically need, the total package of a folder will be lighter and and carry more compact than a fixed blade + sheath of equal blade length.

[Menipo]

REX 45 corrodes very easily, almost like Super Blue. It is among the hardest steels I've used and sharpens surprisingly easily, but honestly I am wanting a stainless back. I just don't feel like the constant maintenance warrants the marginal practical advantage in edge performance.

I have never tried any of those steels but, conceptually, that was my hypothesis: in the tables that I have seen S110V, for instance, has a higher edge retention and the increase in hardness of K390 is not really significant. For that reason I am so interested in knowing the opinions of you, Forumites, who have used them in reality (tables are many times pure theory).

[Woodpuppy]

M4 was my intro to “exotic” steels, and I still have much more time with it than either K390 or REX45. I sharpen on ceramic rods/stones, though I reprofile on CBN rods. Order of difficulty in my limited experience sharpening all 3 is M4 -> REX45 -> K390. K390 edge holding is better than either of the others, but it’s more of a chore to sharpen. If Spyderco were to offer a finer grit option in CBN stones that would make life easier; bonded cbn (as opposed to surface-coated hollow steel rods) would be really awesome!

I’d like to experience K390 in an Endura or P4LW to keep cost down, but I’m in love with the Military platform since for the last 6 months I’ve been teleworking and can carry whatever I please. At the same time I’ve been considering a VG10 Endura just for ease of maintenance and because it’s not a sprint, it’s replaceable. And then Spyderco dropped the Pacific Salt 2 in LC200N!! So many wants, while my needs are already so well met.

[Enactive]

I've been waiting to respond to this thread until i got around to touching up my REX45 and K390. Until now, in my knife purchases, i had prioritized sharpening response over higher edge strength and wear resistance. My "higher end" steels until now were CruWear, LC200N, HAP40 (not used much so far), s30v, VToku. I am excited about REX45 and K390 in large part because i understand them to be relatively easy sharpening for how bad@ss they are! :cool: :spyder:

While i like my regular stainless (S30V, VG10, Sandvik) and ultra stainless (H1, LC200N), I also really like tool steels and other steels that are made to prioritize other characteristics over stainlessness. Horses for courses, as they say.

I have had REX45 in my pocket for work (remodel carpentry/ construction) and on my own time (mostly in town, some in the woods and mountains as the pandemic allows) for a little while now. My REX45 knives are a Native LW which i've had since early April and a Manix 2 LW that i got at the end of August. I carried the Native some, but have carried the Manix more. In fact, the Manix has had a lot of carry time since i got it. I have a handful of Native 5s and other members of that family, but this was my first Manix.

I have been quite impressed with REX45 for it's strength and wear resisitance. I do not have a great need for ultra wear resistance, but i do really like very strong and stable edges. One anecdote to follow:

At work, while installing a tongue and groove hemlock ceiling, i was shaving a board which had been cut out around a light can, but needed more space and was already fastened in place (d'oh!). While shaving the board to create clearance I accidentally jammed the edge with some force into steel light can hardware (d'oh! again). I was like, well crap, looked at the edge and couldn't see any damage at all! :cool: :spyder: For me this is what steel like REX45 is mostly for-- for making up for human error. I do like to try different steels out, largely because i am a very curious person, not so much because i need them. It is nice to find the steels that suit my uses best.

I suspect that some of my other favorites like CruWear and LC200N would have shown some damage from the same treatment. REX45 is growing on me. I have high hopes for K390 too.

As for corrosion resistance, i have been pleasantly surprised by both REX45 and K390 so far. I have carried the REX45 much more-- including in my front pocket for a ~20 mile/ ~5000 vertical ft. hike this past summer and daily for a month or more at work in late summer. I have not found any signs of corrosion yet. I do keep the knives dry and have wiped them down with mineral oil here and there.

As for grindability-- I haven't done any reprofiling, thinning nor repair. I have touched up the Native a couple of times on the brown/medium SM rods. I just touched up the Manix for the first time this morning. I have to say that REX45 touches up quite easily. I did buy some CBN rods for when i need to do more serious sharpening of harder steels, but i have not needed to use them yet.

I just acquired my first K390 in the form of a Delica-- also my first Delica. :cool: :spyder:

I have barely used it. I have high expectations. This Delica is ground thin and it was sharp when it arrived, but i touched it up a little bit on the brown/medium SM rods when i touched up my REX45 this morning. It responded wonderfully to just a few passes on each side at 30 deg.

I will add more comments with more use if i find anything noteworthy.