SR101, S30V, INFI - The Toughest Steel?

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Blain

Blain

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SR101, S30V, CPM3v, BG42, INFI, L6, S7

Which one of these steels is the toughest and most durable, and why?
 
According to my knowledge - nothing's better than INFI! Knife steel is not only toughness but also flexibility, wear reistance and stainlessness! Busse connected all these features in one with quite a big finesse.

L5, L6, S7 - carbon steels, I havent noticed these ones are ever used as knife steels.
 
I can't speak for toughest, but for edge holding in abrasive material, I would have to rank:

1. Infi
2. SR101
3. S30V

The first 2 are probably separated by about 30%, and S30V is down a long way. It's performance for me so far has been unimpressive.

I also have seen both Infi and SR101 respond very well to steeling with a grooved steel. Plus, they also respond quite well to DMT stones after the steeling doesn't work anymore.
 
L6 when heat treated properly (or even somewhat improperly) will result in a blade that is tougher than any stainless...probably tougher than INFI....edge holding will be on par with the others too....but sharpens a whole lot easier.

Of course, alot of this is subject to proper geometry...etc etc
 
Blain said:
[SR101, S30V, CPM3v, BG42, INFI, L6, S7]

... the toughest and most durable, and why?
Click to expand...

First off these can quickly be groups into three main catagories :

1) S30V, BG-42 - *low* durability, very brittle stainless steels with next to low impact toughness

2) SR-101 - high flexibility and overall solid edge toughness due to the differential temper and inherently non-brittle nature of SR-101, many times over tougher than the first list .

3) 3V, L6, INFI - all very flexible and impact resistant steels, to pick the more durable one you would want to be very careful in choosing the maker as the grind and heat treatment could move the steels from one over the other.

Swamp Rat does such a good job with their SR-101 it could easily jump up here as well, it isn't as tough as INFI, but is tougher than some blades made out of 3V and L6 because of differences in geometry and heat treatment.

4) S7

S7 is a shock steel, it is actually optimially designed to take heavy loads. For reference its impact toughness is ~twice that of 3V. There are not a lot of people using S7 as a knife steel.

-Cliff
 
Why don't many people use it as a knife steel?

What about these blades which are made of up to 120+ layers of L6, 1095 or O2 steel from http://www.blacksmithrick.com/bladesmithing.html ? Would these blades be tougher than Infi? I always heard that layered steel was much stronger than a single block forge.

chapman_bg.jpg

112 layers of L6 and 1095 steel


001%20.jpg

112 layers of structural steel, 01 tool steel and 6150 truck spring, differential heat treatment.

003.jpg

160 layers of 01 tool steel and 1095 high-carbon steel, differential heat treatment.
 
Blain...in the actual term "toughness"...with Damascus steel.....probably not tougher than most plain carbon steels or L6, 5160, etc....

However, damascus has the "potential" to be an extremely aggressive cutting steel if patterned and heat treated correctly. But of course, not all damascus blades are done for performance....just pattern in alot of cases.
 
You have to pick a steel in the stock you can work with, if you can't get S7 in 1/4" thick sheets then knifemakers who only do stock removal would have problems, then you have to look at how to heat treat it.

Ricks knives should certainly be very tough, like this one :

http://www.blacksmithrick.com/images/bladesmith/007.jpg

Differentially tempered L6, or this one :

http://www.blacksmithrick.com/images/bladesmith/lawnmower-blade.jpg

Which was made from a lawnmower blade. Nice knives in any case, thanks for putting up the link to his work.

-Cliff
 
Funny how VG10 has proven to be superb in blades from Fallkniven in particular. Toughness never an issue.

S30V is much tougher than most stainless steels in reference to sideways loading. I have several knives in this steel and my Strider Tac AR in particular has no issues with strength or toughness. In fact it can out chop 4" fixed blades...
 
The General,

Don't Fallkniven's knives consist of 420J2 sandwiched around the VG10? Also, were some to complain that they weren't tough, it's a safe bet that a 100 or more knuts would shout "they aren't prybars".
 
Some of the blades are laminated, but the classic A1 model is not (though a laminated version is available also)

I own the A2 field knife and the Idun, both are laminated steel. However I also own several other knives in this steel and never had even the slightest concern that VG10 is not a tough steel.
 
The General said:
Funny how VG10 has proven to be superb in blades from Fallkniven in particular. Toughness never an issue.
Click to expand...

VG-10 isn't a tough steel, if anything it is on the brittle side for stainless. No where near the toughness of carbon steels like 1095, let alone something like L6.


.... S30V is much tougher than most stainless steels in reference to sideways loading.
Click to expand...


I have broken it prying. It has low ductility, the elastic -> plastic region is very narrow. The strength is high of course as are all high alloy steels. The longitudinal toughness is the same as 440C and other similar steels thus it will fracture just as readily, which I have also seen in use.

-Cliff
 
S-7 is the toughest commonly available steel when hardened as it is intended. It has very little edge holding compared to, oh, just about anything! CPM 3V looks like the best tough-plus-edge-holding, though maybe INFI is in that range too but I can't find objective data on it.
 
I made my first knife out of S7. A large convex ground bowie. I had the heat treatment done by Roger Linger and the hardness ended up at 57 Rc. While true that it does not hold a edge as long as most other steels, cutting carpet dulls it fairly quickly, it is a very easy steel to sharpen. I didn't do that great of a job at grinding out the knife, I think that the edge ended up thinner then it should have for the kind of knife it is and for its intended use. That being said the edge has yet to chip or roll and this is with a good bit of tough chopping. I have not used anything made in INFI so I can't compare it to that but it is tougher then anything else that I have played around with.
 
Steel FAQ

There's a newer version of Joe's excellent article which includes"
INFI
INFI is currently only used by Jerry Busse. In place of some of the
carbon (INFI contains .5% carbon), INFI has nitrogen. The result
is a non-stainless steel that is nevertheless extremely stain
resistant (informally reported at close to D-2, or even better),
incredibly tough for a high-alloy ingot steel, and with extremely
good wear resistance.
 
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