Whats the Differance????

R

RicBrannon

Joined
Sep 27, 2001
Messages
328
Ok, I've heard a lot about this new Super Stainless Steel CPM S30V, also the S60V & S90V. They are suppose to be the bomb for knife steels. (Then you have INFI, which I'm not totally convinced isn't a trick of heat/cryo treatment.) So, what is the difference between ATS34/154CM and the CPM S-V steels? Are they really that much better? I have noticed that a lot of makers have gone to these steels. Is it because they are new or because they are better?
Now you all probably know I an a tracker knife fan. I have talked to a few different people about steel for a long term survival knife and most say high carbon because of easy of sharpening in the field. Something like 0-1 or D2. They say it's easier to take care of in the field. Now, I'm of the belief that if something doesn't need sharpening it's easier to sharpen just because you need to do it less. Now if ATS34 is harder to run across a stone but you only need to sharpen it once to D2s' 4 sharpenings then I'd rather have ATS34. (Just an example) Now I have a Busse MeanStreet and I use it for everything. I've owned it for 6 years now and carved countless bow drill kits, sharpened spears, split wood, gutted fish, dug holes and cut barbed wire, to name a few. Digging the hole was really the only thing that dulled it, the wire did put a small ding in the edge but it came right out with a few swipes on a fine stone. Point is, I carry my MeanStreet because I've had it all this time and only had to sharpen it may 3 or 4 times and it never took that long because it never gets that dull. So, What is the difference between these two, the ATS34s & the CPM S-Vs? Thanks for your help.

Ric
 
S30V has vanadium in it to promote a tougher, stronger edge. Some folks have noticed chippoing in their edges, others haven't. For me, S30V holds an edge for a really long time. 154CM (ATS34's twin) lacks vanadium and doesn't hold an edge as long for me. All things being equal (bwahahahaha), S30V will resist chipping, breaking, dulling, and corroding longer than 154CM. It would be neat to see a Paul Bos treated ATS34 knife compete against an S30V knife of the same shape and proportions treated by the same gentleman. Unfortunately for us knifeknuts, most folks who could afford such tests don't care and don't want to waste that money.

Hope my diatribe was at least moderately useful.
 
Using Crucible's description, S30V holds an edge 22% longer/better than 154CM (ATS 34 is the Japanese version), is more corrosion resistant and has 4 times the strength across a transverse section.
154 CM is light years ahead on polish, though.
D2 is a cold work, high alloy tool steel, not generally classed as a "Carbon steel". It has 1.45-1.55% Carbon, but also 11.5-12%Chromium and ~1% Vanadium and Moly. It holds and edge at least as well as 154 CM and is almost as corrosion resistant. It is a "bear" to polish though.
In my opinion, S30V is the best available of all steels for a using knife for those of us who take them out in the boondocks. The other S__Vs are even better at holding an edge, but are not nearly as tough. CPM 3V is tougher and holds an edge about as well, but with much less Chromium will rust easily.
 
Thanks for the input. What do you mean the other S-Vs hold an edge longer but aren't as tough? I would think longer edge holding would translate to tougher.
And what about INFI? I believe it has some cobalt content which makes the edge bounce back or roll over rather than chip. The INFI knives I have had seem to stay sharp forever, once you get them sharp that is. The cobalt also makes it highly magnetic. I set my BMLE next to my monitor and it took all the color out of it, turned it green. Basically I'm looking for the toughest steel with the best edge holding I can find. If the other S-Vs hold an edge better than S30V but aren't as tough how much of a difference in toughness is there? If the margin isn't that great I think I would rather go with the edge holding. Thanks again for your help.

Ric
 
Ric,

In INFI already does everything you ask of it, why look elsewhere? If you're still going to look, why not try Crucible's M2 high speed steel?
 
Originally posted by thombrogan
Ric,

In INFI already does everything you ask of it, why look elsewhere? If you're still going to look, why not try Crucible's M2 high speed steel?
Click to expand...


Well if I could get a couple pieces of INFI out of Busse I would but they won't sell it and I'm not sure were else to get it. If there is another place to get it. Any suggestions would be greatly appreciated.
What are the properties of the Crucible M2? Why a high speed steel? Thanks again.

Ric
 
How does this sound???:D :D


CPM® REX® M35HCHS*
(AISI M35)
CPM REX M35HCHS is a 5% cobalt modification of M2 high speed steel used almost exclusively for hobs and other gear cutting tools where higher red hardness is required. Made by the Crucible Particle Metallurgy process, CPM REX M35HCHS has excellent machinability and grindability characteristics.

Typical Chemistry Typical Applications
Carbon 0.98% Gear Hobs Milling Cutters
Manganese 0.70% Shaving Cutters Shaper Cutters
Silicon 0.40%
Chromium 4.05%
Vanadium 2.00%
Tungsten 6.00%
Molybdenum 5.00%
Cobalt 5.00%
Sulfur 0.22%




* The addition of .20/.25 S provides a uniform dispersion of small sulfides throughout the structure, resulting in machinability and grindability benefits with no deleterious effect on toughness.


Annealed Hardness: BHN 225/255

Annealed Hardness (Mill Process): BHN 277/302
Standard Full Anneal: BHN 225/255

Machinability in the annealed condition is approximately 50% of W1 Tool Steel (1%C).
 
M2 is tougher and holds a better edge than S30V or 154CM, but it's not stainless. I have a few Benchmades made with the steel (folders and fixed blades) and, when I finally get the edge with my Sharpmaker, it's very nice.

According to Crucible Service, M2 is a bit lower on the Charpy C-Notch table than D2 (154CM not mentioned as it's not a tool steel). The relative wear resistance of M2 is about 33% higher than 3V (or 3V is 25% lower) and both are much higher than D2 and A2 and dramatically dwarfed by 10V and 15V. M2 exhibits better deformation resistance than D2 when both are at a 62Rc hardness (though how much better was not described).

Element breakdown is as follows:

Typical Chemistry
Carbon 0.85%

Manganese 0.30%

Silicon 0.30%

Chromium 4.15%

Vanadium 1.95%

Tungsten 6.40%

Molybdenum 5.00%

Sulfur 0.03% max. (0.10%)

If wading through technical data is your bag, check this out for more info on Crucible goodness including their "Killer V" steels.
 
According to the Crucible website, S30V has slightly better wear resistance than 3V and M2, which are about equal.
S30V has 4 times the Charpy C-notch strength of 154 CM and 440C which are about the same as D2. CPM 3V has a much higher strength than all of these.
CPM 10V, 15V, S60V and S90V are even more brittle than M2.
Check out the specs at: <www.crucibleservice.com/index.cfm>
 
On the Crucible site on the HIGH SPEED STEELS FOR CUTTING TOOLS CHEMISTRIES & PROPERTIES chart it often shows a big gap between WEAR
RESISTANCE & TOUGHNESS. What exactly do they consider the differance between the two? The ability to stay sharp vs. how brittle the steel is? And what exactly is RED HARDNESS? Charpy C-notch?
By the chart it would seem that the wear resistance of the CPM S-V steels is quite high while the toughness is quite low. Whats the trade off? Does that mean I can clean, dress and skin 50 elk but the blade breaks on the first log I chop for the fire? I am looking for something that would be good in all areas but it seems that very few really meet in the middle so to speak.

Ric

P.S.
No I don't like plowing through technical
data but the mix look impressive.
 
Properties of materials: Toughness is resistance to breaking from impact or from bending back and forth. Strength is resistance to stretching or to compression -- two independant properties, tensile strength and compression strength, and bending strength depends on both because when you bend something you stretch it on the outside of the bend and compress it on the inside of the bend. Rockwell hardness is resistance to indentation. Abrasion resistance is resistance to (believe it or not) abrasion. Etc.

Edge-holding depends on various combinations of properties in proportions depending on the material you're cutting. It is not a simple property.

Some examples: Try making a blade out of glass. Good hardness, but if you try to cut anything more resistant than the hair on your arm the lack of toughness will cause the edge to chip. Try making a blade out of copper -- good toughness, but lack of hardness will cause the edge to indent. Etc....

Search the Reviews & Testing Forum for more information. If nothing else you'll soon realize there is no simple answer to "Which steel is better?"
 
Originally posted by RicBrannon
By the chart it would seem that the wear resistance of the CPM S-V steels is quite high while the toughness is quite low. Whats the trade off? Does that mean I can clean, dress and skin 50 elk but the blade breaks on the first log I chop for the fire? I am looking for something that would be good in all areas but it seems that very few really meet in the middle so to speak.
Click to expand...
I believe that is the reason S30V was developed, to give the best compromise of qualities.
HERE is a direct link to crucible's cutlery steels. Clicking on the steel designation will give more info on the individual steel (pdf).
A very wide range of properties, so it's impossible to make blanket statements about them.
 
I understand. Thanks. From looking at all the charts and chem data on Crucible's site I think I may have found my steel. I'll let you know after I do some tests. Thanks again for all the insite.

Ric
 
Good luck with CPM® REX® M35HCHS. Half of me hopes it's the best cutlerly steel and that you've made the discovery of a century. The other half hopes it's great, but not so great that I have to type it everytime I daydream about the ideal folder or fixed blade.
 
For pure edge holding, I would guess the Crucible's CPM REX 121 is the ultimate. It is a super high speed steel that hardens to HRC 70.5 at optimum toughness.
Just try to work that with the average knifemaking tools.
 
@CPM steels is made by powder metallurgical method.This process is the way that solid state is made from powder metal.
So oxiside formed on powder surface is easy to be included.
But ATS is made from liquid metal.And Finer microstructure is
achieved by carbide reaction.And also oxiside and oxgen content in steels is not so high level.So it is easy to make mirror finish of steel surface.
 
Originally posted by thombrogan
Good luck with CPM® REX® M35HCHS. Half of me hopes it's the best cutlerly steel and that you've made the discovery of a century. The other half hopes it's great, but not so great that I have to type it everytime I daydream about the ideal folder or fixed blade.
Click to expand...


Don't worry, if I find one of these is the best and start using it regularly I'll give it some cool 4 letter acronym and not tell anyone what it really is.

Anything can be worked with normal knife making tools. It's just a matter of how much time and energy you want to expend in the process.

Ric
 
There are some bizarre and wonderful knife steels out there. And there are enough entrepid knifemakers who will eventually use one or more of those types of steel.

S30V looks like the best of the current bunch, with Talonite / Y6K being another specialty non-steels that really makes the mark. The issues of hardness, toughyness, wear resistance and alloys and components have been discussed. BUT I think there's more to it than that.

WHY ARE THOSE 440C, ATS-34, CARBON STEEL knives out there still selling so well ? And thats because people are familiar with them, can use them, know how to sharpen them and understand their abilities, and drawbacks in the field. Not that many people who buy custom knives actually aim to field dress 50 deer. Those who do that sort of thing seem to go for the el-cheapo butchers knives that have to be steeled every few minutes anyway.

Also, with the other steels, most makers can use them, grind them, forge them, know their habits to a tee, and can buy them in enough quantities to get good and making a good knife out of it. And they can do it at a price that buyers can afford. You gotta remember than whatever the steel, no matter 420HC or S90V, the key to cut is in the HEAT TREAT. And not everyone HT's the same way.

Unfortunately, some of the very, very wear resistant steels out there are near impossible to grind / work and you'll find that price you pay on the purchasing end is accordingly higher to account for tooling, time and effort.

A lot of S30V knives I suspect are actually going to collectors at the moment. I COULD BE WRONG, VERY WRONG. But I suspect that those same collectors who want a using knife might plonk out on a high-quality but less pricey working grade model. Eg.- a nice ATS-34 version as a user. If S30V becomes available in the way that 440C is relatively more available, and cheaper, more makers would use it and more buyers would use it.

Just a few ideas. I wonder if the attraction of these newer steels has to do with the "Wow" factor, ie.- "My knife can do this .... "

Cheers. Jason.
 
Price of steel is only really a small figure in the total price of a knife, esp a custom / hand crafted one, but ...

Where I live is not the easiest to get knifemaking supplies. The way it works out, for equivalent sizes -

1084 forging bar stock - $0.50/inch, O-1 carbon (PG) - $1.00/inch, 440C - $2.50/inch, ATS-34 - $3.30/inch, RWL-34 - $3.50/inch, BG-42 - $5.00/inch, CPM440V (S60V) - about $9.00/inch, CPM S30V - $10.00/inch.

Ie.- here, S30V is 3x the price of ATS34 and 2x the price of BG-42 and is starting to approach the price of commercially available Damascus. Ie.- you can't realistically make a 4inch hunter from S30V for $200 when the steel alone already could cost $90 (9inch bar)

Of course its more available in the USA, but once you factor in shipping, the price rises dramatically.

Just my experience.
 
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