steel vs steel

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Dec 21, 2006
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So this CPM M4 has me curious. Edge retention out the wazoo, or so it seems, and I'm thinking about ordering some from Niagra (they have 1/8), making a few knives, one for myself to keep. I'll send it out for heat treat. My question being....ceteris paribus....can the edge retention on CPM M4 be much more noticeable than well done (as opposed to medium rare!) 52100 or W2? I have ZERO experience with it, saw the numbers (composition), and it has me intrigued. Thanks for any help, advice, or experience!!!
 
52100 and W2 are my favorite steels. I do some forging and stock removal. Those are very good steels for what I make. But I recently joined Bladesports and have been using a loaner knife in CPM M4 and the edge retention is ridiculous. It is a good bit better than 52100 or W2. However, it is very expensive and difficult to sharpen.
 
Yes, very pricey. :eek: Difficult to sharpen....I can sure see why! From what I have gathered from the "interweb", everyone said the same thing. I'm guessing it would be like sharpening a very hard stainless steel, which is a downer, because I like the relative ease of sharpening the more simple carbon steels. To be honest, the steel's ability is probably above MY ability to turn it into a nice knife! A case of the clay molding the potter, perhaps?
 
There's a reason the vast majority of BladeSports competitors are using CPM-M4... that reason is extremely high edge-retention and fine edge stability coupled with very good toughness.
 
It is the current hot stuff in the competition cutting world indeed! Disclaimer....I won't be entering any cutting competitions! The idea is just to make a hunting knife or EDC type to have a steel with super high edge retention, and to compare it with the other two steels, W2 and 52100. I wish it was available thinner (and cheaper)....it would be nice to make the wife a santoku from it. End grain cutting boards and proper technique....would NEVER need sharpening!
 
1/8" isn't too bad. With full flat grinds and full distal taper that should make an outstanding santoku or chef's knife. Talk to your HT guy about hardness... I think you could easily have it run at 62 or 64Rc for a thin slicer/hunter.

Definitely do your complete grind and surface finishing before HT unless you just want a very basic belt finish. You do not want to hand-sanding anything with that kind of carbide content after it's hardened...
 
My understanding is that the wear resistance is a trade off with how fine the edge can get. Even S35VN will not take the edge W2 or 52100 will. The carbides are larger, but the particle technology helps.
 
The idea is just to make a hunting knife or EDC type to have a steel with super high edge retention

Pick your goal- if you want high edge retention then you can do much better with something like S110V. I've heard that exotic steels like K390 and Maxamet are even better. But it is unlikely that any of these are as tough as M4.

Steel is always a tradeoff- toughness vs. edge retention, pick which one you prefer and compromise on the other.

I sliced up a bunch of boxes with my M4 folder a few months ago, and it dulled faster than I thought it would given its reputation. I've read of tests between M4 and S110V where S110V did many times better. Now that I have a knife in S110V that is similar to my knife in M4, I'm anxious to stock up on cardboard and try that test myself.
 
Warren, that is another trade off when we are picking our steel choices, isn't it? Do we want an edge made out of large super hard tungsten and vanadium and chromium carbides that doesn't take quite the edge but stays sharp for a super long time, or do we want a super fine grained edge that takes a wicked fine edge, but might not last quite as long? I know the White Steel fans will say the edge retention of White Steel can be right there with the Blue or better...if it's done right. I'm not after the ULTIMATE in edge retention. As Mr "Micarta" mentioned, there are better alloys out there for that. Maybe A11, or the mentioned S110V, or even the Tyrannosaurus Rex stuff :D!
 
Samuraistewart, I think 52100 is my personal best compromise between the traits. I don't have enough history with W2 yet, but from what I've read, it's very similar in performance.
 
M4 is my favorite user steel. It responds well to stropping (I was surprised) and has great stability at lean sharpening angles at high hardness. I would love to get a chunk and make a nice wharncliffe with it.
 
Along this same line, how would cpm-d2 compare to 52100 and w2?

I had two D2 knives, I traded one and still have the other. They hold a toothy edge a very long time. D2 has very large carbides. This is only two examples, but consistent with what the chemistry suggests.
 
Note: should take my results as fwiw because me-abby-normal :p

I just completed a 5 to 6 hrs of tired & bored cardboard shredding over a 2 weeks period with a 52100 knife.
http://www.bladeforums.com/forums/s...-quenched-52100-knife?p=13788314#post13788314

Projected W2 (steel sourced from Don Hanson) knife would has similar performance as 52100.

Prelim/informal cardboard cut tests(in feet) - iirc: K390 1k-2k ft, s110v 1k-1.5K, s90v 600ft, 20cv/m390 600ft and less than 400 ft [m4, d2, s30v, cpm154].
 
I'm always impressed when someone, like Bluntcut, takes the time to perform cutting tests with various steels. Of course, not any one test is the standard (even CATRA), but it helps to give me an idea of what is going on real life, and not just by "the numbers".
 
If it's available, I'd rather use cts xhp.

Or Elmax. CPM-D2 is pretty good stuff but it never really turned out to be all it was cracked up to be IMO. It's basically just clean D2 (takes a much better finish and finer edge) without much if any other useful improvements.
 
I get a kick out of blade guys discussing steels. " I've been using CPM-OLD, and it is OK, but how about XYZ?", ...."No, ABC is better, John D. Biguy uses it.",...."Naw, I heard UPYRS can slice up Woolly Bears better than both of those.",...." What if you make MNO sort of like XYZ, wouldn't that be cool!"

It is sometimes like the nerdy guys in the comic book shop arguing about supermodels and saying, " Gisele is sexier than Heidi.", and the next guy saying, "I'd throw them both out of bed for Kate.". Truth is these guys will most likely never get the chance to compare any of them, .......umm, the steel guys, I mean. The comic book shop guys got no chance with pretty much any gal.

Most modern knife steels will make a superb knife. Most modern knife steels are not "plug and play". You have to learn what makes them shine and how to feature that attribute. This takes practice, testing, and recordkeeping, as well as sticking to one steel for the most part.
The guy who spent 30 years married to his cute high school sweetheart and learned how to ring every chime on her is probably much happier than the guy who dated the entire cheerleader squad and now has three unhappy divorces, or the fellow who had one frustrating and expensive date with Heidi Klum.....metallurgically speaking, of course ;)

I'm looking forward to when the NBBT in knifemaking ( next bigger and better thing) is how well you can work a chosen steel not what is the new hot steel of choice by Spyderco.

I still stand by my oft repeated recommendation - "For most knifemakers, three steels can make 99.9% of any knife you would ever want. IF you learn how to work them properly." Find the three that fit you and your equipment. Get them from a reliable source and in enough quantity to assure consistent results. Learn their every trait and secret in HT and edge ability.
One simple carbon type ( eg. 1084,5160/O-1)
One high carbon type ( eg. 1095/W2/Hitachi white/52100)
One high alloy stainless type ( eg. K390/CPM-S35VN/elmax/AEBL/etc.)


There is one knifemaking tool that hardly ever gets mention in these discussions, and that is a good 20X loupe. Looking at a magnified edge is very revealing. The difference between two good cutting edges can be huge under magnification. The difference in wear can also tell you a lot. A cheap used binocular microscope is great, too. They can be found surplus for very little. To phrase it in simple koan, "You can't observe what you can't see."

The good thing about these discussions is that we are talking metallurgy and testing.....based on actual user info about tweaking HT and sharpening techniques. Even if you never date your particular favorite supermodel, it is nice to learn what "bedroom secrets" the fellows who run in her circles find out about her, and try them out on your AEBL sweetheart .....metallurgically speaking, of course ;)
 
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