Heavy-Use Steel

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About 3V...

CPM-3V material is designed to provide maximum resistance to breakage and chipping in a highly wear-resistance material. CPM-3V material offers impact toughness greater than A-2, D-2, Cru-Wear or CPM-M4 material, approaching the levels of S-7 and other shock resistance material, while providing excellent wear resistance, high hardness and thermal stability for coatings. CPM-3V is intended to be used at HRC 58/60; CPM-3V can replace high alloy tool steels in wear applications where chronic tool breakage and chipping problems are encountered.

Seems like it would be up to any worldly knife use or abuse. ;)
 
I agree with the recommendations for 3V because of the desire for both toughness and wear resistance. It's not difficult to find steels with better wear resistance or with more toughness, but I don't know any that will beat 3V in both areas.

Sadly, these kinds of threads have more to do with feeding the inner ninja ego than with practical knife usage.
 
I know I've always got a jackhammer in my bag, right next to my MRI and lathe. I'd have more, but I like to travel light...

Anyway, I think 3V seems to be the champion here, though some of those other materials look rather well suited... Is there a chart that directly compares the properties of knife steels to each other?

Also, and I know it's not the greatest by any means, but how does titanium compare to steels? I've heard it has problems but I don't have enough experience with it to know exactly what they are.

Also, if appropriate, does anyone know if the steels named off in this thread would be good for a rigid lock pick? I know it's off topic, but I make lock picks and it's kind of a rule of thumb to use spring steels so they don't break, but this thread got me thinking about what materials I could use for them besides that. Primarily a material that doesn't bend like a spring steel, but instead is strong enough to be rigid and not break unless heavily abused.

But back to the knife steels, a good edge really is important. I'm not saying I want the steel not break, I'm saying I want the steel to not break and hold a nice edge. An edge that could whistle through a piece of paper.

Okay, this is starting to sound a bit demanding... I'm not asking magicians... But still, is 3V the closes to that there is? What about s35V like in Sebenza knives, is it different? I've heard a lot about VG# steels, but I'm not sure exactly what they're good for or how they compare...

I of course have a certain level of understanding beyond what I'm asking, but I want to make sure that I ask the most broad questions I can in order to get the most information I can.

Thank you all so far, I never expected this forum to be so... ... Fruitful.
 
Dash Lambda said:
Also, and I know it's not the greatest by any means, but how does titanium compare to steels?
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Compare how? There are about a half dozen formal terms used to characterize metals. Hardness, toughness, strength, etc etc. Then a bunch of informal things like cost, ease of sharpening, etc etc etc.
 
Dash Lambda said:
But back to the knife steels, a good edge really is important. I'm not saying I want the steel not break, I'm saying I want the steel to not break and hold a nice edge. An edge that could whistle through a piece of paper.
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Again, your question is not quite there. Close though! Edge holding and edge taking are not the same thing. Just about any steel will take an edge that will whistle through paper. Will it hold it? Maybe. maybe not.

"Sharpness" isn't really a steel property.
 
Steel Toughness Chart2.jpgHope this chart helps. As you can see 3V is not even on the same planet as S7 for toughness. S5 gets 60RC and is even tougher than S7. The problem is that S5 is hard to find in flat ground. Steel Toughness Chart.jpg
 
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I figure if torturing stuff is more important to you than actually making or finding a real use for blades then maybe you should get hold of an old truck leaf spring, sharpen it up to your best ability and then 'go to town'. No one will be offended, depreciation will not ensue and your arms will get sore.
 
FFK said:
View attachment 457320Hope this chart helps. As you can see 3V is not even on the same planet as S7 for toughness. S5 gets 60RC and is even tougher than S7. The problem is that S5 is hard to find in flat ground. View attachment 457319
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Did you look at the charts you provided to see that the edge retention/wear resistance for those extra tough steels is absolute crap?
They would make astoundingly terrible knives, which is why people aren't making knives out of them.
 
stabman said:
Did you look at the charts you provided to see that the edge retention/wear resistance for those extra tough steels is absolute crap?
They would make astoundingly terrible knives, which is why people aren't making knives out of them.
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That's a fair point for some of the high-wear steels, but we do have high-wear steels with good toughness and they make wonderful knives: 10V, S90V, S110V, K390 are all super high wear and make great knives. I have knives in all those steels. CPM M4 is a steel with pretty good balance of toughness and high wear.

But really, we need to match the steel, blade and edge geometry, heat treat to the intended use, then the discussion gets good.
 
Twindog said:
That's a fair point for some of the high-wear steels, but we do have high-wear steels with good toughness and they make wonderful knives: 10V, S90V, S110V, K390 are all super high wear and make great knives. I have knives in all those steels. CPM M4 is a steel with pretty good balance of toughness and high wear.

But really, we need to match the steel, blade and edge geometry, heat treat to the intended use, then the discussion gets good.
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Those steels have good toughness and a bunch of edge retention.
I was referring to the steel with almost no wear resistance but extra high toughness that the person with the charts kept going on about.

I don't want an S7 knife.
 
IMHO, some steels that are well-matched to your preferences would be:
  • CPM-S35VN
  • ELMAX
  • CPM-M4
  • CPM-154 (NOT 154CM as that is an inferior steel)
  • RWL-34 (NOT ATS-34 as that is an inferior steel)
  • CTS-XHP


To my understanding, you want a folder and based on what you said it sounds like you want excellent wear resistance AND excellent toughness. I find the above steels to really accelerate in both categories.

S35VN is a nice steel because it performs well all-around. It holds an edge well, it does a pretty good job at cutting abrasive objects (like cardboard), it's very tough, it has excellent corrosion resistance, and it is not that difficult to sharpen. ELMAX, CPM-154, and RWL-34 also give these characteristics.

Unless you plan to use a folder in an unusually abusive manner, the steels used on fixed blades that yield tremendous toughness may not be justifiable due to higher costs, sometimes lesser wear resistance, and sometimes very poor corrosion resistance. CPM-3V is an awesome steel, with it's primary downside generally being price and availability. I've honestly not ever used a folder anywhere near to the degree that would get my money's worth of it's toughness, as it is such a tough steel! I do not know of any steel with toughness similar to or better than 3V to have as good as edge retention as 3V (they may exist...just never encountered them myself.)

If you do want an abuse-all folder, Striders in CPM-3V are built to handle the toughest of tasks possible (with the trade-off being less suitability for smaller tasks.)

Benchmade’s Contego in CPM-M4 is less expensive, has a very practical blade for small and heavy tasks alike, holds an edge very well, is not difficult to sharpen, and is tough as hell.
 
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FFK said:
OK........If your really taking a trip to hell and back, 3V will break or chip. Try to buy a full tang fixed out of S5, or CPM 1V.
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Unless running the knife over with an Abrams tank is a possibility, 3V is not a steel that breaking or chipping is a concern with, IMO. In fact, it was made for the purpose of reducing breaking and chipping.

3V improves in toughness (including chipping resistance) over steels like A2, CruWear, and CPM-M4. A2 is tougher than M4. CPM-M4 and CruWear are significantly tougher than steels like ELMAX or S35VN. ELMAX and S35VN are significantly tougher than most stainless steels. With an impact toughness of 85/113 @ 58 HRC, that is over twice that of A2. That’s a lot of toughness.

Further, unlike A2, S7, and many other tool steels with exceptional toughness, 3V has surprisingly good wear resistance at a level that most steels with excellent shock resistance have nowhere near. The lack of wear resistance of steels like S7 makes them generally not great steels for knife blades. As the OP wants edge holding, 3V is far more practical than S7 in this case (and I would argue in most any case.)

Destruction tests done on CPM-3V fixed blades speak where actions are more important than words or numeric ratings. There are videos on YouTube of people trying to break 3V fixed blades by doing whatever abusive work they can physically manage (like driving through metal pipes with sledgehammers, batoning reinforced concrete, putting the tip in the vice and pounding the other side with a sledgehammer, etc.), and yet are unable to cause catastrophic failure, or even severely deform the basic working edge. These videos show that 3V has a toughness far, far beyond what virtually any normal (and abnormal) usage would exceed.

Like INFI, 3V especially shines with large knives when used in a fashion that places significant shock force on the blade. And like INFI, it someone manages to break a 3V blade, they are a really special person...


The wear and toughness properties of CPM 3V make it an excellent alternative to shock-resistant steels such as S7 or A9, where they typically wear out too quickly, but where grades such as A2, CruWear, or CPM M4 tend to fail by breaking or chipping. CPM 3V offers the highest impact toughness of any tool steel with this range of wear resistance.
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http://www.crucible.com/eselector/prodbyapp/tooldie/cpm3vt.html
 
stabman,
I don't want a S7 fixed blade either(S7 remelt might work).....S5 is what I'm after or possible CPM1V. No Cryo !
 
FFK said:
View attachment 457320Hope this chart helps. As you can see 3V is not even on the same planet as S7 for toughness. S5 gets 60RC and is even tougher than S7. The problem is that S5 is hard to find in flat ground. View attachment 457319
Click to expand...

If you're going to link to my chart, at least give me credit and some background. UNO, those values are at room temperature, and are Charpy C-notch tests. Since they are sourced from different places, you might as well add +/- 25% to any given value, which can happen in a single lab, let alone different sources. It takes a pretty big difference to really mean anything. The one that blows them all away is 4340. I just don't know of anyone making knives from it. Hawks and axes, yes, but not knives.
 
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