Cpm Rex 121

P2P

P2P

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Jul 24, 2010
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Looks like spyderco has been putting some rex 121 blades on some of there models, sage and para 2 recently. I was fortunate enough to pick one up.

There has been some brief discussion online of people who keep referencing either cardboard (and being petrified by staples) or glass in order to test their blades. Im looking for some other evidence from users here.

I use my knives pretty hard, I dont abuse them, but I'm not nice. As an industrial electrician, its not uncommon for me to strip THHN 500kcmil wire with a pocket knife. Enough force that ill put the tip of the wire on a piece of wood, and lay my weight into the blade to strip it. S45vn, cruwear, magnacut, even 15v have held up.

Ive been mean to a military 2 in 15v for over half a year now. Its my favorite steel at the moment. Its cut tarps in trenches banging against rocks, torqued on some zipties the other day. From what ive read online today about 15v, I'd think that would not be doable.

So I read the same now about rex 121. I might just beat the tar out of it and see what happens, but seems like everyone online is skeptical about its toughness. Ive wondered for quite some time how much toughness a folder really needs.

So anyone hear put some miles on rex 121? Any broken tips? Like to hear from those who who have been surprised or disappointed by its performance.
 
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P2P said:
Looks like spyderco has been putting some rex 121 blades on some of there models, sage and para 2 recently. I was fortunate enough to pick one up.

There has been some brief discussion online of people who keep referencing either cardboard (and being petrified by staples) or glass in order to test their blades. Im looking for some other evidence from users here.

I use my knives pretty hard, I dont abuse them, but I'm not nice. As an industrial electrician, its not uncommon for me to strip THHN 500kcmil wire with a pocket knife. Enough force that ill put the tip of the wire on a piece of wood, and lay my weight into the blade to strip it. S45vn, cruwear, magnacut, even 15v have held up.

Ive been mean to a military 2 in 15v for over half a year now. Its my favorite steel at the moment. Its cut tarps in trenches banging against rocks, torqued on some zipties the other day. From what ive read online today about 15v, I'd think that would not be doable.

So I read the same now about rex 121. I might just beat the tar out of it and see what happens, but seems like everyone online is skeptical about its toughness. Ive wondered for quite some time how much toughness a folder really needs.

So anyone hear put some miles on rex 121? Any broken tips? Like to hear from those who who have been surprised or disappointed by its performance.
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It's more brittle and fragile than any other steel used for knives, but that doesn't mean it will break in "normal" use. It's not going to be much more fragile than more commonly used steels like S125V and M398. Of course, everyone has a different idea of normal use.

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I like it, but it does pick up rust.
 
I have all these , specifically REX 121 and Maxamet .
I thiink those two are very similar in hardness / brittleness .
I would say you can do all you mentioned but if you drop it on a big rock (while in a hole) or concrete you will probably break the tip at the very least . I have heard / seen at least one image of a broken knife (more than the tip )from being dropped .

I've babied mine so no actual hard use . My edge did get a bit MICROSCOPICALLY coarse from use even though I took it through many diamond grits to 8,000 DMT Extra Extra Fine (the stone with the dimples) . My MICRO fracturing was most likely from two things . I reprofile the hell out of it and I did it with a VERY COARSE 60 grit ZirconiaAlumina sanding belt double back taped to a flat surface (Edge Pro plate) .

From what I have gleaned since then these scratches contributed to the MICROSCOPIC break down of the edge . I am sure this will resolve itself after more sharpenings with only finer diamond stones .

Don't get me wrong ; it still cut like a devil while slicing but it's push cutting tanked .

Yah bottom line maybe keep it for "controlled" volume cutting like the dirty canvas but not so much rough and tumble stuff .

I am VERY glad I got mine but it has taught me that my all time favorite steel is M4 .
I have 15V as well . I just resharpened mine a couple nights ago . Some what similar experience ; with careful use the hair whittling edge left but still was a darned good cutter . The M4 keeps that high sharpness that I crave longer.

A couple of mages for yah (I can't leave any knife stock , it seems ) :
Top knife is REX 121 (in a Cobalt Blue G-10 handle )
Second knife is Maxamet (Black G-10)
Third knife is obviously 15V (got a little crazy with the handle there but I'm liking it ) .
Fourth knife obviously is M4 with a little Mod Mod to the blade shape . My Precious ! ! !

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PS: Some of the stuff I used for reprofiling the REX 121 on the first try . In the old handle .
Yep ! He's a BAD BOY !
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DeadboxHero said:
Geometry has a MASSIVE effect but unlike steel, different geometries don't have cool names like different steels to capture the imagination of casual enthusiasts.
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This is your chance, Shawn.

Petite-Small-Medium-Large-Extra Large-Big Brown Bear

Of course, most of us would be better served starting off immediately with Big Brown Bear, which counterintuitively would be the most svelte of all.

☺️
 
REX 121 is a solution in search of a problem. Economics are why it's gone, no matter what excuses anyone around here has.
 
Ron Texas said:
REX 121 is a solution in search of a problem. Economics are why it's gone, no matter what excuses anyone around here has.
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Ron, what do you base all of your claims upon...can you please share your bona fides, and on what basis you should be considered an industry insider?

If you're going to make claims, which are not just your opinion, please back them up.
 
Blues said:
Ron, what do you base all of your claims upon...can you please share your bona fides, and on what basis you should be considered an industry insider?

If you're going to make claims, which are not just your opinion, please back them up.
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My statements are based on publicly available facts. I won't mention this again.
 
Ron Texas said:
My statements are based on publicly available facts. I won't mention this again.
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So, would you refer to this special sort of research you do as ‘confirmation bias speculation’, or just ‘bloviating’?

Those are my statements based on publicly available facts.. I won’t mention it again, either.
 
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