CPM REX 45 | Edge Performance
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Re: CPM REX 45 | Edge Performance
I'm wondering if the chipping people are experiencing with Rex 45 is due to having not sharpened the edge enough to get rid of the burnt steel from factory grinding?
Re: CPM REX 45 | Edge Performance
I am! It was a comment on how fickle we are. I do look forward to trying Rex45 but you can see that reputations hang on a thread in the frenzied world of the internet.TkoK83Spy wrote: ↑Thu Oct 21, 2021 7:41 pmI really hope you're joking?? This post is making me twitch.R100 wrote: ↑Thu Oct 21, 2021 7:30 pmI am really surprised and disappointed by the accounts of Rex45 chipping. It has put me off a purchase I was considering. I have a number of S30v knives taken back very thin behind the edge and given a 30 degree microbevel. I have not experienced chipping with fairly heavy use unless I hit steel or rock or do something stupid. The only conclusion I can draw from this thread is that Rex45 is a long way behind S30V as an edc steel and I would be crazy to use it. What am I missing?
Dan
I've never met a bad steel in a Spyderco or had trouble with chipping - even with zdp189 and S110v.
Sorry to give everyone a scare.
Dan
Re: CPM REX 45 | Edge Performance
Are you trying to insult the people that are providing honest reports of chipping?R100 wrote: ↑Thu Oct 21, 2021 8:45 pm
I am! It was a comment on how fickle we are. I do look forward to trying Rex45 but you can see that reputations hang on a thread in the frenzied world of the internet.
I've never met a bad steel in a Spyderco or had trouble with chipping - even with zdp189 and S110v.
Sorry to give everyone a scare.
Dan
Would you rather we just said nothing at all or that REX45 is invincible?
Re: CPM REX 45 | Edge Performance
I get chips in nearly any steel at my job, mostly stripping large wire. I found that on my rex45 burnt orange shaman, freehanding a slightly convex bevel on a muddy king deluxe 1k produces a long lasting edge that doesn't chip at all for me. My top choice for a work knife.
It did chip with a guided system edge at 17 DPS with a 20 DPS microbevel though
All of the folks having issues with chipping - just increase the angle of the bevel or microbevel, just like you would with any other steel. What's so confusing? Or convex it.
It did chip with a guided system edge at 17 DPS with a 20 DPS microbevel though
All of the folks having issues with chipping - just increase the angle of the bevel or microbevel, just like you would with any other steel. What's so confusing? Or convex it.
Re: CPM REX 45 | Edge Performance
Would switching to an all diamond abrasive sharpening regime help with chipping?
Re: CPM REX 45 | Edge Performance
I doubt Rex edges burn much. It's a heat-retardent steelCycletroll wrote: ↑Thu Oct 21, 2021 8:31 pmI'm wondering if the chipping people are experiencing with Rex 45 is due to having not sharpened the edge enough to get rid of the burnt steel from factory grinding?
"Some call me...Tim?"
Re: CPM REX 45 | Edge Performance
I’ve used Rex 45 a pretty good amount, and I don’t think I’ve ever noticed chipping…. I consider it the most abusable steel I’ve used. I sharpen on DMT diamond stones, if that makes a difference.
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Re: CPM REX 45 | Edge Performance
I think that even though it is a temper resistant tool steel the thin cross-section of a knife blade may still be susceptible to weakening through overheating during the sharpening process. My 0.02¢Paraguy wrote: ↑Wed Oct 05, 2022 7:08 pmI doubt Rex edges burn much. It's a heat-retardent steelCycletroll wrote: ↑Thu Oct 21, 2021 8:31 pmI'm wondering if the chipping people are experiencing with Rex 45 is due to having not sharpened the edge enough to get rid of the burnt steel from factory grinding?
Spyderco Caly 3.5 Super Blue user, Astute enthusiast, and geometry advocate.
- Deadboxhero
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Re: CPM REX 45 | Edge Performance
Two years ago I was curious what would happen if I gifted a brand new Spyderco Military model in CPM REX 45, 8% carbide volume, 67.0 HRC and low fracture toughness to a "non knife geek" heavy knife user. This knife has been put through **** it was even left outside in the rain for 2 weeks.
He was an interesting test subject to explore this question because never in his life has he spent more than $50 on a pocket knife and does not care about blade steel so their was no bias from him.
His most used knives were Buck 420HC, I met him when I was a professional knife sharpener and his knives would blunt completely smooth very quickly so I could see objectively his knives were being heavily used and why he checked all the boxes for an excellent candidate to further explore a curiosity.
Well, the knife was put through complete ****, I was surprised it was in one piece, the g10 peel ply is worn smooth so I got a lot of time in the hand from the end user. What was most shocking was that the edge retention was subjectively and objectively better than softer, tougher steels he had experienced.
Without asking leading questions he explicitly stated,
"Yeah that's the best knife I've ever had, just keeps cutting"
He was genuinely stoked about the performance.
Most knives in his use blunted to +1000g on the BESS tester, the softer tougher steels had little resistance to deformity and the edge would smash down in use quickly, I was surprised to see the edge under 500g Bess after the first YEAR.
This knife was only sharpened once when I met him again at Shot Show 2022 in Las Vegas at the Spyderco booth, it was sharpened to 200g BESS with the Spyderco sharpmaker using the diamond rods and finished on the white ceramic.
Its been almost a whole year since it was sharpened and it was nicely maintaining a sub 500g BESS edge with heavy use. NOT +1000g BESS with other steels I've seen from him, so there is real world evidence that the increased cutting edge retention seen in controlled testing does cross over to the reality, the problem is that these steels are expensive and difficult to process, heat treat, and you can't use Grandpa's arkansas stones.
Edge tested 1" from heel
Edge tested 1" from tip
Translation of BESS to paper cutting sharpness
In his perception, if the knife is still physically cutting it is still sharp. What the Rex 45 did was it did not blunt completely smooth at the edge and it could still physically cut without extreme force and slipping compared to a "tougher" softer steel that would have blunted smooth with lots of physical cutting.
The biggest take away I feel for readers is that one should give things a try first hand and see if it works or doesn't work for their preferences and uses.
I'm pretty sure the CPM REX 45s low toughness would be better seen if we duct taped it to a poll and tried to cut a concrete wall in half, but there are probably better and cheaper tools for demolition work.
He was an interesting test subject to explore this question because never in his life has he spent more than $50 on a pocket knife and does not care about blade steel so their was no bias from him.
His most used knives were Buck 420HC, I met him when I was a professional knife sharpener and his knives would blunt completely smooth very quickly so I could see objectively his knives were being heavily used and why he checked all the boxes for an excellent candidate to further explore a curiosity.
Well, the knife was put through complete ****, I was surprised it was in one piece, the g10 peel ply is worn smooth so I got a lot of time in the hand from the end user. What was most shocking was that the edge retention was subjectively and objectively better than softer, tougher steels he had experienced.
Without asking leading questions he explicitly stated,
"Yeah that's the best knife I've ever had, just keeps cutting"
He was genuinely stoked about the performance.
Most knives in his use blunted to +1000g on the BESS tester, the softer tougher steels had little resistance to deformity and the edge would smash down in use quickly, I was surprised to see the edge under 500g Bess after the first YEAR.
This knife was only sharpened once when I met him again at Shot Show 2022 in Las Vegas at the Spyderco booth, it was sharpened to 200g BESS with the Spyderco sharpmaker using the diamond rods and finished on the white ceramic.
Its been almost a whole year since it was sharpened and it was nicely maintaining a sub 500g BESS edge with heavy use. NOT +1000g BESS with other steels I've seen from him, so there is real world evidence that the increased cutting edge retention seen in controlled testing does cross over to the reality, the problem is that these steels are expensive and difficult to process, heat treat, and you can't use Grandpa's arkansas stones.
Edge tested 1" from heel
Edge tested 1" from tip
Translation of BESS to paper cutting sharpness
In his perception, if the knife is still physically cutting it is still sharp. What the Rex 45 did was it did not blunt completely smooth at the edge and it could still physically cut without extreme force and slipping compared to a "tougher" softer steel that would have blunted smooth with lots of physical cutting.
The biggest take away I feel for readers is that one should give things a try first hand and see if it works or doesn't work for their preferences and uses.
I'm pretty sure the CPM REX 45s low toughness would be better seen if we duct taped it to a poll and tried to cut a concrete wall in half, but there are probably better and cheaper tools for demolition work.
Re: CPM REX 45 | Edge Performance
LUV real world test stuff.
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Re: CPM REX 45 | Edge Performance
It is pretty cool, the problem is it's difficult to compare apples to apples without more control seems there could be kind of a paradox in the knife community where controlled testing is not good enough and real world testing is not usable. Yikes.
Of Course realistically they're supposed to go hand in hand.
The problem is it took two years to get this anecdotal real world account.
Given how many steels there are in existence, none of us would live long enough to see testing like this on every steel.
Re: CPM REX 45 | Edge Performance
Coming from someone who is seriously interested and invested in paleontology, I am well acquainted with the reality of testing hypotheses. It’s really long term.Deadboxhero wrote: ↑Thu Dec 01, 2022 2:53 amIt is pretty cool, the problem is it's difficult to compare apples to apples without more control seems there could be kind of a paradox in the knife community where controlled testing is not good enough and real world testing is not usable. Yikes.
Of Course realistically they're supposed to go hand in hand.
The problem is it took two years to get this anecdotal real world account.
Given how many steels there are in existence, none of us would live long enough to see testing like this on every steel.
That said, the field has advanced extremely quickly in the last few decades and is still picking up the pace. There are a few dozen new dinosaurs named every year and that’s just dinosaurs and just taxonomy. I mean, the evolution of the palate in birds ( it’s more significant than that sounds really) was completely redefined in a study on a prehistoric toothed bird published yesterday and just days before that a new species of dinosaurs similar to Tyrannosaurus was formally published,
and much more.
This advance is caused partly by an expanding body of researchers, but also new technologies, better methods and techniques, and greater public access to knowledge. And all based on long term data collection, passion, and the effort of now many years of collective scientific investigation alongside real world” amateur/professional effort in the field.
All of this is in common with the kind of landscape I think we’re seeing in whatever we’re doing with knives recently. At least, it all feels very familiar to me.
Maybe it’s at a bit smaller scale here, but it’s due to no small endeavor by you, BBB, and other giants in the knife world, like Spyderco, Larrin Thomas, Phil Wilson, Ed Schempp, and more.
rex121 is the king of steel, but nature’s teeth have been cutting for hundreds of millions of years and counting :cool:
Re: CPM REX 45 | Edge Performance
Nice to see even more evidence as to why I've found Rex45 to be my favorite steel these past 4 years or so now! I think I give my knives a pretty good run for their money working daily in a warehouse, but that Military there looks like it has some stories! Pretty awesome stuff, thanks for the feedback on that Shawn.
15 's in 10 different steels
1 - Bradford Guardian 3 / Vanadis 4E Wharnie
1 - Monterey Bay Knives Slayback Flipper / ZDP 189
1 - CRK Small Sebenza 31/Macassar Ebony Inlays
1 - CRK Large Inkosi Insingo/ Black Micarta Inlays
1 - CRK Small Sebenza 31 Insingo/Magnacut
-Rick
1 - Bradford Guardian 3 / Vanadis 4E Wharnie
1 - Monterey Bay Knives Slayback Flipper / ZDP 189
1 - CRK Small Sebenza 31/Macassar Ebony Inlays
1 - CRK Large Inkosi Insingo/ Black Micarta Inlays
1 - CRK Small Sebenza 31 Insingo/Magnacut
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Re: CPM REX 45 | Edge Performance
That's an impressive "test."
Because desolate places allow us to breathe. And most people don't even know they're out of breath.
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Re: CPM REX 45 | Edge Performance
Thanks Shawn and Cl1ff! It is anecdotes like these that make this group so rewarding!
Shawn, I love that you put your own money and passion into a gift for science that also benefitted an unwitting study participant!
Shawn, I love that you put your own money and passion into a gift for science that also benefitted an unwitting study participant!
Re: CPM REX 45 | Edge Performance
If nothing else it appears REX45 doesn’t require any sort of special treatment whatsoever!!! I don’t think M4 would have fared as well, much as I love it.
Re: CPM REX 45 | Edge Performance
Great report Shawn! Do you have any idea how an S90V Military may have held up in that situation? Higher edge retention than REX45 but maybe it would be brought undone by lower edge stability due to larger carbides?Deadboxhero wrote: ↑Thu Dec 01, 2022 2:53 amIt is pretty cool, the problem is it's difficult to compare apples to apples without more control seems there could be kind of a paradox in the knife community where controlled testing is not good enough and real world testing is not usable. Yikes.
Of Course realistically they're supposed to go hand in hand.
The problem is it took two years to get this anecdotal real world account.
Given how many steels there are in existence, none of us would live long enough to see testing like this on every steel.
Dan
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Re: CPM REX 45 | Edge Performance
Thanks Cl1ff
Cl1ff wrote: ↑Thu Dec 01, 2022 3:29 amComing from someone who is seriously interested and invested in paleontology, I am well acquainted with the reality of testing hypotheses. It’s really long term.Deadboxhero wrote: ↑Thu Dec 01, 2022 2:53 amIt is pretty cool, the problem is it's difficult to compare apples to apples without more control seems there could be kind of a paradox in the knife community where controlled testing is not good enough and real world testing is not usable. Yikes.
Of Course realistically they're supposed to go hand in hand.
The problem is it took two years to get this anecdotal real world account.
Given how many steels there are in existence, none of us would live long enough to see testing like this on every steel.
That said, the field has advanced extremely quickly in the last few decades and is still picking up the pace. There are a few dozen new dinosaurs named every year and that’s just dinosaurs and just taxonomy. I mean, the evolution of the palate in birds ( it’s more significant than that sounds really) was completely redefined in a study on a prehistoric toothed bird published yesterday and just days before that a new species of dinosaurs similar to Tyrannosaurus was formally published,
and much more.
This advance is caused partly by an expanding body of researchers, but also new technologies, better methods and techniques, and greater public access to knowledge. And all based on long term data collection, passion, and the effort of now many years of collective scientific investigation alongside real world” amateur/professional effort in the field.
All of this is in common with the kind of landscape I think we’re seeing in whatever we’re doing with knives recently. At least, it all feels very familiar to me.
Maybe it’s at a bit smaller scale here, but it’s due to no small endeavor by you, BBB, and other giants in the knife world, like Spyderco, Larrin Thomas, Phil Wilson, Ed Schempp, and more.
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Re: CPM REX 45 | Edge Performance
Thanks, yeah it's quite surprising how durable it is.
It certainly looks like an antique after only 2 years.
It certainly looks like an antique after only 2 years.
TkoK83Spy wrote: ↑Thu Dec 01, 2022 6:39 amNice to see even more evidence as to why I've found Rex45 to be my favorite steel these past 4 years or so now! I think I give my knives a pretty good run for their money working daily in a warehouse, but that Military there looks like it has some stories! Pretty awesome stuff, thanks for the feedback on that Shawn.
- Deadboxhero
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Re: CPM REX 45 | Edge Performance
I'm glad it was enjoyed took 2 years to make :D