CPM REX 45 | Edge Performance

[Sharp Guy]

Funny how the Rex45 was so hyped and desired. Now you never hear anything about the 2 models released in this steel. Safe queens I'm assuming? My guess is it becomes more of a production steel we'll get more testing and feedback. Don't even see many pics of these knives posted in picture threads!

I think recently we have been faced with a lot of great offerings and a variety of steel choices. 204p 4v 20cv maxamet cpm cruwear dlc/non dlc etc. I’m sure we will soon see performance discussions. To-date, I carried and used my para 3 in Rex 45 for about two weeks. I then sharpened and put it aside. Personally I think it takes a fantastic edge. I finished on 800 diamond stones and stripped from 4 micron to .5 diamond emulsion. I was able to whittle hair both ways. I don’t care to nor have the time to do rope or cardboard testing. I agree the hype has faded a bit but trust more experienced knife testers will chime in.

I agree that at least part of the lack of hype has to do with all these great releases lately. I'll freely admit that I haven't carried or used either my REX knives much. I was on the fence about buying them in the first place. The steel seemed like it was too close to HAP40 and I didn't really care if I had any more burnt orange knives. Then I heard that Spyderco was running the REX 45 steel harder than their HAP40 so I decided to jump on the bandwagon. Once I received mine the honeymoon ended kind of quickly. I started messing around with some previous purchases and some other knives started to drop. I've had no intention of my REX knives becoming safe queens yet they are at the moment. There's only so much time in my life and only so many opportunities to cut stuff. The REX knives aren't going any where and I'm sure they'll get their day in the sun at some point. In the meantime...it's back out to the garage for me to continue reprofiling my Delica HAP40 WC and to watch more football, racing, & hockey. :)

[TkoK83Spy]

You guys are definitely right about all these new releases seemingly every week. It's been crazy the past few months! I have a Rex45 Para 3 and am guilty of the same...plus its so hard for me to put away my beloved M4 and M390. Spyderco has such a variety of steels...my friend is a diehard Benchmade guy, my only knife friend that's REALLY into knives like most of us. He's interested in Spyderco, and we trade knives at work for a day sometimes. He says he doesn't want to get into Spyderco because he knows he'll go broke!

[megawatt]

You guys are definitely right about all these new releases seemingly every week. It's been crazy the past few months! I have a Rex45 Para 3 and am guilty of the same...plus its so hard for me to put away my beloved M4 and M390. Spyderco has such a variety of steels...

Your telling me. This is what I have received In the last 3 weeks. I have not been able to put down my cru-ware para to start cutting with any of these fine blades.

[The Meat man]

I'm going to do a rope cut test next when I get time, before I got to try the knives I was guessing Rex45 would out cut M4 on rope due to the chemistry and hardness. However based on what I'm seeing off the stones I don't think Rex 45 has the aggression to smoke M4 with a toothier edge on manilla rope. We'll see what happens.

After that it will be interesting to test the edge stability and toughness with more controlled destructive edge testing.

Hey Deadboxhero,

Have you done any more testing with CPM REX 45? I'm particularly interested how it compares to Maxamet (since I'm more familiar with Maxamet). Have you done that rope cut test you spoke of?

I'm really curious how REX 45 compares, edge retention/wear resistance wise, to say Maxamet or S110V or K390 or M4.

Ankerson, where are you? :)

[Deadboxhero]

They may be closer on rope then we think. Hardness does play a factor. Currently I have no time to test. I'm investmenting my time in hand sanding super steel knives :D

I'm going to do a rope cut test next when I get time, before I got to try the knives I was guessing Rex45 would out cut M4 on rope due to the chemistry and hardness. However based on what I'm seeing off the stones I don't think Rex 45 has the aggression to smoke M4 with a toothier edge on manilla rope. We'll see what happens.

After that it will be interesting to test the edge stability and toughness with more controlled destructive edge testing.

Hey Deadboxhero,

Have you done any more testing with CPM REX 45? I'm particularly interested how it compares to Maxamet (since I'm more familiar with Maxamet). Have you done that rope cut test you spoke of?

I'm really curious how REX 45 compares, edge retention/wear resistance wise, to say Maxamet or S110V or K390 or M4.

Ankerson, where are you? :)

[Midnightrider]

Mine should be here in a few days.

[ejames13]

Surprised to see such little feedback on this steel. I have been really enjoying mine. Not very scientific but here are some observations. I'm going to use Cruwear as a comparison since that's the other steel I'm most familiar with.

- Seems to hold a keen edge for a long time, considerably longer than Cruwear, even when cutting through cardboard.
- Very easy to bring the edge back to a high level of sharpness with brown rods or just some stropping. Probably on par with Cruwear in terms of ease of sharpening.
- Likes to hang onto a burr, much more so than Cruwear. I don't hate it though, because it lets me know I still need to clean up the edge. Other steels will feel sharp even when there's some burr remaining. Not REX. In fact, I was struggling at first trying to figure out why I couldn't get it as sharp as I like, then I realized there was a tiny burr. As soon as that burr is gone though, shoo whee! Laser sharp.
- Staining hasn't been bad for me. I washed it and didn't use compressed air to blow out the pivot, which left me some small water stains. Nothing major though. I'd put the corrosion resistance at less than Cruwear and greater than M4.

Like I said, NOT scientific. Just some thoughts from my use I thought others might be interested in.

[anycal]

In regards to performance, specifically with the newly released Military. Has anyone put theirs through any type of extensive cutting?

For whatever reason, although very sharp out of the box, the factory edge hasn't stayed sharp for very long. Far from a steel expert, and the comments below are not grounded on any scientific experiments, but this has been my first impression.

When I have to take down large amount of cardboard, I reach for the Military. Most of these tasks in the past were handled by the green 204P. Using the same type of cardboard (well, from same product but maybe the cardboard has changed, although I can't really tell), the REX 45 Military came off much duller than the 204P. Maybe this is expected based on the steel, maybe it was the cardboard, maybe it is the factory edge? I don't know.

Just wondering what kind of experience are you having with your Military REX 45?

Although I haven't re-profiled it yet, it sharpened up pretty quick. I should be able to run the same type of cutting test/task next week. I may end up re-profiling it by then.

[Cycletroll]

I'll be getting my Rex Mille on Friday. Will report back once I've put her to work!

[Baron Mind]

In regards to performance, specifically with the newly released Military. Has anyone put theirs through any type of extensive cutting?

For whatever reason, although very sharp out of the box, the factory edge hasn't stayed sharp for very long. Far from a steel expert, and the comments below are not grounded on any scientific experiments, but this has been my first impression.

When I have to take down large amount of cardboard, I reach for the Military. Most of these tasks in the past were handled by the green 204P. Using the same type of cardboard (well, from same product but maybe the cardboard has changed, although I can't really tell), the REX 45 Military came off much duller than the 204P. Maybe this is expected based on the steel, maybe it was the cardboard, maybe it is the factory edge? I don't know.

Just wondering what kind of experience are you having with your Military REX 45?

Although I haven't re-profiled it yet, it sharpened up pretty quick. I should be able to run the same type of cutting test/task next week. I may end up re-profiling it by then.

I would expect edge retention to improve with another sharpening or two. It may still be slightly less than 204p, but you gain a lot in edge stability, or strength if you will. Also, are the edge angles the same? If new REX millie has a more obtuse angle you will get less edge retention out of it.

[ferider]

In regards to performance, specifically with the newly released Military. Has anyone put theirs through any type of extensive cutting?

For whatever reason, although very sharp out of the box, the factory edge hasn't stayed sharp for very long. Far from a steel expert, and the comments below are not grounded on any scientific experiments, but this has been my first impression.

When I have to take down large amount of cardboard, I reach for the Military. Most of these tasks in the past were handled by the green 204P. Using the same type of cardboard (well, from same product but maybe the cardboard has changed, although I can't really tell), the REX 45 Military came off much duller than the 204P. Maybe this is expected based on the steel, maybe it was the cardboard, maybe it is the factory edge? I don't know.

Just wondering what kind of experience are you having with your Military REX 45?

Although I haven't re-profiled it yet, it sharpened up pretty quick. I should be able to run the same type of cutting test/task next week. I may end up re-profiling it by then.

Haven't really used my new military yet, but on my PM2, the edge holds for quite long. Similar to my M390 copy.

Now, the best thing about the new Rex 45 Military is that you could use it to engrave your 204p blade; I should try .... but then, maybe not :)

[Ankerson]

Currently in the process of testing the REX 45 Military. :spyder:

Interesting so far, that HRC hardness has to be way up there from what I am seeing.

Will likely be done in the next week or so, testing it, rope, cardboard, HD zip ties, power cord, wood.

[Bloke]

Currently in the process of testing the REX 45 Military. :spyder:

Interesting so far, that HRC hardness has to be way up there from what I am seeing.

Will likely be done in the next week or so, testing it, rope, cardboard, HD zip ties, power cord, wood.

Very much looking forward your findings Jim. :cool:

[The Meat man]

Currently in the process of testing the REX 45 Military. :spyder:

Interesting so far, that HRC hardness has to be way up there from what I am seeing.

Will likely be done in the next week or so, testing it, rope, cardboard, HD zip ties, power cord, wood.

Very much looking forward your findings Jim. :cool:

Ditto!

[crazywednesday]

Currently in the process of testing the REX 45 Military. :spyder:

Interesting so far, that HRC hardness has to be way up there from what I am seeing.

Will likely be done in the next week or so, testing it, rope, cardboard, HD zip ties, power cord, wood.

THANK YOU!

[Ankerson]

Finished the rope cutting, it did excellent IMO.

Added here:

https://www.bladeforums.com/threads/ran ... pe.793481/

[abbazaba]

Thank you for everything you've taken the time to do! FWIW, the Providence is an insta buy for me when it drops.

On some level I was expecting HAP40 performance when I got the PM2, but it had surpassed my expectations two fold. M4 has been my baseline reference and preferred carry, but after my experience with REX45 (and K390), I'm just really hoping I get the luxury of these steels in as many models/options as M4, because I may like them better.

Thanks again!

[Deadboxhero]

Finished the rope cutting, it did excellent IMO.

Added here:

https://www.bladeforums.com/threads/ran ... pe.793481/

Wow, 840 cuts, cut more then 4v and M4, Very nice. That hardness really helps.

Thanks Jim

[TkoK83Spy]

Making me regret every second of passing on the opportunity for the PM2 when it dropped and only grabbing the Para 3. I say that because I also have the Para 3 in M390, 4V and M4...only have the PM2 in S30V and S35VN. *repeatedly smashes head into wall*

[The Meat man]

Interesting! Thanks Jim!

That is not quite what I thought it might come to. I thought it would be closer to Maxamet, at least over a thousand.

Still that is a terrific amount of cutting. Higher than K390.

How did you find the edge bite or aggression to be compared to other HS tool steels like Maxamet, K390, CPM M4, etc.?