CPM S90V, CPM 3V or CPM M4 for Knife/Machete

G

Godeye

Joined
Dec 18, 2013
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I am new to knife making and wonder, which steel is better for chopping woods.
My priority is edge holding and just enough toughness, that it won't chip at chopping.
I don't really care, if it is stainless or not.

I found some results of those steels:
CMP S90V: hrc 28, toughness: 26 J
CPM M4: hrc 63.5, toughness: 27 J
hrc 65.5, toughness: 38 J
hrc 62, toughness: 43 J (in third link, not second)
CPM 3V: hrc 58, toughness: 113 J
hrc 60, toughness: 95 J
hrc 62, toughness: 53 J

There are links for all three steels:
http://www.crucible.com/eselector/prodbyapp/plastics/s90vp.html
http://www.crucible.com/eselector/prodbyapp/plastics/cpm4hcp.html
http://www.crucible.com/eselector/prodbyapp/plastics/cpm3vp.html

I konw S90V has reputation of superiority edge holding, but this is very relative, because of all factors, especially hardness-toughness balance.
I prefer S90V (edge holding), but i don't have any experience, so my question is:

1. At first, what is max. hrc of S90V for the job?
2. Is 4mm thickness enough for machete made out of S90V or is it much better 7mm?
3. Would 3V at 62 hrc hold an edge better as S90V at 58 hrc? (while still twice as tough)
Or maybe 3V at even higher hrc and comparable toughness?
4. Same with M4, would M4 at 63,5 hrc (comparable toughness) hold an edge better as S90V at 58?

Any help would be very helpful.
 
CPM-M4 seems to dominate the Bladesports competition along with some 521000. You may want to start you research on those knives.
I assume you are talking about a large camp knife or machete and cost isn't an object..

I am pretty new as well and if there is one thing I have learned is that the HT and Geometry are everything.
I decided to buy good equipment and do my own heat treat in house which has been a blessing for me not to mention living on the same street as Richard Bridwell.

If it were me I would figure out my dimensions and make sure a known HT company could take in a larger piece like a machete in your chosen material.
 
butcher_block said:
of the steels you listed 3v Rc60 all day every day
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Absolutely :thumbup:

CPM-M4 dominates cutting competitions because it has extremely high wear-resistance, and can hold an insanely thin/keen edge throughout a minute or two of very fast, very intense cutting and chopping demonstrations.

I don't know a single comp-cutter who recommends CPM-M4 for long-term-use as a survival, homesteading or combat tool.

CPM-3V at 58 or 60Rc flat-out smokes every other alloy I know of in rough, long-term use. It can take a truly crisp, fine, keen edge, has really good wear-resistance, and truly outstanding toughness... it's reasonably corrosion-resistant, too.

3V generally performs far above and beyond "plain" carbon steels, and every tool or stainless steel I know of. There, I said it.
 
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S7 steel is tougher than 3V. I use it a lot for machetes, no problem with impact toughness and it's easy to sharpen. It's also a simple steel to work with and heat treat. Stains easily but not really prone to rust. Overall S7 is an interesting steel to consider.




Custom Machetes
http://akiblades.com
 
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I feel that 3V blade has much less spring property than plain carbon steel, one you blend it to some point it will permanently blended.

I have used and tested a Diaz Tool's chopper in CPM-M4 heat treated by Peter, and the edge holding is on par with a well teat treated 52100 chopper.
 
If cost and availability don't hinder you from S90V i say why not?

A machete for my use, i would prefer 52100- easily available, stays sharp and tough, easy to sharpen too with smooth pebbles from stream.
The only point i see better in S90v is that it's more stainless.
 
I would say 3v, s7, or A2. I have heard horror stories of new makers trying to get a good finish on s90v.
 
3V will be the best. S90V is pretty tough but you will end up damaging the edge much more easily and you have to worry about catastrophic failure.

Its been show time and time again that 3V is superior to M4 in impact
blades.

As for stainless im currently experimenting with AEB-l for machetes. So
far so good at 57-58 rc edge and spring spine. It seems promising.

I use 52100 for my machetes and honestly think its the best steel out tthere for a long thin impact tool. Im going to try 3V and s7 in the future but im completely blown away by the performance of 52100 in such a big blade.
 
For chopping wood, I would rather concentrate on weight, balance and geometry of the blade, not on the steel itself.
Softwood or hardwood?

Anyway, I don't expect much of this thread. Just another user who read a bit about super-steels :D
 
I honestly feel that using S90V for a machete is not a solid choice. To me it's a bit like taking a sports car off road. Knives dull in various ways, which is a significant aspect when choosing a steel. While it does offer a lot of abrasive ware, a machete is unlikely to dull significantly in that way. More likely it will dull from impaction, and even chipping/rolling from likely contact with dirt, knots, small rocks, etc if you use it like a traditional machete.

In that case you want a very tough steel that can achieve reasonably hardness. I honestly think something like S7 is your best bet.

Another aspect to consider is how you are going to maintain it. If you use it like a traditional machete, it will take damage to the edge, and unless you are using a power equipment to maintain it, the lower grindability of steels like 3V, which comes from it abrasive wear, is actually going to go from benefit to disadvantage.

Of course, the thickness you will take the edge too and the edge angle will have a significant impact here. But if you are going to leave it very thick (.045+) with a relatively high inclusive edge angle (40+) the steel choice becomes much less important.
 
i tire of the sharpen ability claim all the time
if you make or buy a custom knife or a high end production knife and cant aford a DMT diafold duel side folding sharpener to keep in your pack you might be doing something wrong. just looked and they are under 40$ i had to look since its been years since i picked up my latest one (16 years since i got my firt one that i still use )
i have had one or 2 in any pack i have been hiking of in the field with for touch ups
3v is only hard to sharpen if you have never used anything but 1084 or 52100 S90v can be a pain on a larger blade but M4 whiel more than 3v i find sharpens better then s90
 
butcher_block said:
i tire of the sharpen ability claim all the time
if you make or buy a custom knife or a high end production knife and cant aford a DMT diafold duel side folding sharpener to keep in your pack you might be doing something wrong. just looked and they are under 40$ i had to look since its been years since i picked up my latest one (16 years since i got my firt one that i still use )
i have had one or 2 in any pack i have been hiking of in the field with for touch ups
3v is only hard to sharpen if you have never used anything but 1084 or 52100 S90v can be a pain on a larger blade but M4 whiel more than 3v i find sharpens better then s90
Click to expand...


I agree that sharpening 3V is not that difficult, especially if you have diamonds, but for many reasons not everyone uses diamonds. However, if you have to take out damage (chip, rolling), or if after lots of use you want to reset the edge bevel, or thin the edge for summertime use, I do think 3V is more tiresome to deal with than the simple carbon steels. Again, I am referencing damage or extensive edge reprofiling. And again, I state this if you do not use power equipment which makes such differences negligible.

I can appreciate people's affinity for 3V, and I was not by any means discounting it. I was simply offering additional perspectives to consider.

As a side note Butch, I saw in the Zwear thread that you use the low tempers for 3v. I wanted to say that from what I understand of the heat treatment process, I like that choice when using 3v for choppers!
 
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Thanx for all replys.

Bob Katilus said:
Are you asking because you want the first knife you plan to make, be out of one these steels?
Click to expand...

I bought and made a few knives and machetes, but nothing so expensive and made out of better steels. Now, I decided to make one of those, instead of buying one, to see the difference and to have my design and all (I spend quite some time for it =)

First, I apologize for not being clear enough. I want to make a large knife and machete - something between, 7 mm thick (I think) and want mostly cut things (that is why I want superior edge holding). But I want, that this knife won't chip or break at cutting wood either (even a little harder wood).

The thing is, there is a company near my home and I can get a little cheaper steel here and don't need to wait...
They heat treat these steels too and HT alone is quite expensive, but very good. And it is a pity to buy much cheaper steel, if it's HT would be a lot more expensive. That is I was looking for these steels.
Another thing is, they have only S90V steel in plates, all others are sticks or much thicker plates (25 mm or ~1"). And I want to make a few smaller knives from that material and HT them at the same time, which will be just for cutting.

So I want to know, is S90V no go for chopping because of chipping?
Another thing, can 3V at very high hardness (for example 62 - 63 hrc) match with S90V (58 - 59 hrc) in edge holding? Or can be 3V even better?
I want to maintain the knife, that's why I don't really care if it is stainless... And I won't be chopping near ground or rocks, for that I have cheaper and easy to sharpen machetes.
If I would make just a machete and just for chopping, it would be definitely 3V or something like that. But I just want to be able to chop wood (without a lot of damage of course), but still, primary cutting.
 
Maybe it's a language difference, but I wouldn't call a 7mm or .280" blade a machete


More like a pocket axe.
 
s90 will out slice 3v no problem since it have more total carbides
when it comes to chopping tho its much less differance and 3v might out gun s90 then (those carbides are first to fall out too)

Cash i took the low temper option due to using the cryo. if no cryo then high temp is a must (all due to having to get rid of al the RA)
 
Interesting reading from Ed Schemmp about CPM-M4.

Ed Schempp said:
There is a tendency for CPM M4 to work harden in the very thin geometry of a knife blade. Blade sports competitors push the limits and some of these very thin blades work harden and fracture or crack after a year or two on competition, and are replaced. Personally I used 52100 clad with 15N 20 for several years, and the knife is still undamaged. For large blades I prefer high Carbon to stainless or high speed steel. I like to think that my blades will outlive me.
There are many special purpose steels that will give exceptional life with light cutting tasks. Many of these steels will be used and do well in folding knives, it depends on what you like in your knife...Tke Care...Ed
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IMO a steel such a S7 that is designed for shock is a better option then the steels listed in the original post.

http://www.burgessknives.com/media/S7.pdf

If you really want to bump things up H13.

Here is some good reference material. LINK

H13 wont give you insane hardness, but it will be good....or...you can keep to a simple carbon steel such as 1055 and heat treat it properly.

From what I have seen with people using machetes here in sub Sahara Africa....simple is better. Machetes get abused far more then most knives and many people will use it to dig out roots and even try to cut down hard woods with it. IMO if you are serious about having a good performing machete a simple carbon steel ground correctly and heat treated well will be better suited then S90V.

My 2 cents.
 
Godeye said:
Thanx for all replys.
So I want to know, is S90V no go for chopping because of chipping?
Click to expand...

S90V is not a good option because of the amount of carbides it has.

Here are references about fatigue cracking and other cracking along grain boundaries.

http://web.mechse.illinois.edu/medi...gliu_ijp.20110408.4d9f59ff0c48a8.29327594.pdf

I strongly advise you to read about microstructure of steels and how important heat treat is.

marthinus said:
Welcome to the forum.

All steels are a mixture of properties with certain pro's and cons. Here are a few basic links to get you started.

Z knives knife steel FAQ

Chemical Elements and their affects

Steel And Metallurgic Terminology Glossary

Different-steel-types by Sandvik

important-factors by Sandvik

knife-steel-knowledge, technical-glossary by Sandvik

knife-steel-knowledge by Sandvik

Steel_Terminology.pdf

Now I cant emphasis the following enough. No matter the steel, if the heat treat is done right you will have a good steel. If the heat treat is a done poorly it will be only a paperweight.

Here is a good book about heat treating:

Thank you to John D. Verhoeven for making this book available to the public.

Metallurgy of Steel for Bladesmiths & Others who Heat Treat and Forge Steel - By John D. Verhoeven (2005)

Then there is one final thing that drastically affects a steels performance. Your ability to sharpen it for your needs. But that is a whole different discussion.
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The influence of grain size on the mechanical properties of steel. Author: Morris Jr., J.W.. Publication Date: 05-01-2001

Grain Size and Material Strength
 
butcher_block said:
i tire of the sharpen ability claim all the time
if you make or buy a custom knife or a high end production knife and cant aford a DMT diafold duel side folding sharpener to keep in your pack you might be doing something wrong. just looked and they are under 40$ i had to look since its been years since i picked up my latest one (16 years since i got my firt one that i still use )
i have had one or 2 in any pack i have been hiking of in the field with for touch ups
3v is only hard to sharpen if you have never used anything but 1084 or 52100 S90v can be a pain on a larger blade but M4 whiel more than 3v i find sharpens better then s90
Click to expand...

As Cashmore points out, it's not a matter of being able to sharpen a steel in the field, it's a matter of being able to repair chips and rolls in the field. You want to be able to fix the blade with a file, not a sharpening stone.

As for wood processing blades... blades don't dull very easily from chopping into wood. You can chop and split wood all day with 5160, 1055 any medium carbon steel, and you won't effect the edge much at all... unless it chips or rolls (as mentioned above.)

S90V for a chopper? Ridiculous! Enjoy the chips (not wood chips.) Really, anything much beyond 55HRC is going to be difficult to repair with a file.
 
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