SR101, S30V, INFI - The Toughest Steel?

The General said:
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.
Click to expand...

Three things:

1. If unlaminated VG10 was tough, wouldn't it be odd for Fallkniven to switch to laminates? Damascas-clad, sure, but otherwise strange for general use.

2. If used within a narrow scope of tasks, VG10 and most others will do just fine, but that doesn't make them tough. Great steels, certainly, but not tough. My favorite steel for folding knives is M2. It's tougher than any cutlery-grade stainless I've used and holds an edge longer than any of them as well, but it's still not as tough as most other low-chrome/non-stainless steels.

3. Back to your comparison of your Strider Tac AR and knives with fixed blades of similar length. Your comparison doesn't mention the thickness of the other blades, if their grinds are similar to the AR, their blade steel, nor if their handles have a similar shape. Were the Strider guys to make an AR with 1084 high carbon steel with all other parameters being equal (length, width, grind, RC hardness of blade), it'd be tougher than their current S30V models (just not as popular and would require more maintenance). I've got some tough folders made with Bohler N690, but at .23" thick, most every steel seems tough.
 
Is A2 toughest steel? BarkRiver making some models out of it.
Thanks, Vassili.
 
These people make swords and knives out of S7. Link . I can't comment on their stuff.

What about 8670? It's a German saw steel John Greco uses (used?) in his knives. I heard somewhere that it is similar to L6 but more stain resistant, but don't know the facts of this matter.
 
thombrogan said:
Three things:

1. If unlaminated VG10 was tough, wouldn't it be odd for Fallkniven to switch to laminates? Damascas-clad, sure, but otherwise strange for general use.

2. If used within a narrow scope of tasks, VG10 and most others will do just fine, but that doesn't make them tough. Great steels, certainly, but not tough. My favorite steel for folding knives is M2. It's tougher than any cutlery-grade stainless I've used and holds an edge longer than any of them as well, but it's still not as tough as most other low-chrome/non-stainless steels.

3. Back to your comparison of your Strider Tac AR and knives with fixed blades of similar length. Your comparison doesn't mention the thickness of the other blades, if their grinds are similar to the AR, their blade steel, nor if their handles have a similar shape. Were the Strider guys to make an AR with 1084 high carbon steel with all other parameters being equal (length, width, grind, RC hardness of blade), it'd be tougher than their current S30V models (just not as popular and would require more maintenance). I've got some tough folders made with Bohler N690, but at .23" thick, most every steel seems tough.
Click to expand...

Well I have used the A2 in the field and I mean USED it! It has chopped hardwood, and performed every action you could possibly imagine short of cutting nails in half! I have used it for prying, chopping, splitting and much more. Never once did I have any problem with toughness or failure. Not once, nadda, zip. As a comparison though, it is quite a thick blade and the steel is running at a Rc of 59 so it is not as hard as it could be. Fallkniven switched to a laminated steel this much is true, however it is offered in addition to their standard VG10 line up. It is only in prying nad very cold weather that I can really see the point of a laminated steel in a smaller blade like my Idun. However I bought them for the "gadget" factor and I am fairly sure that is one of the reasons they offer the option, its simply cool! My good Friend Trond Pedersen really rates laminated steel for daily use and I was lucky enough to get the chance to make a knife with his help made from a billet of hand made laminated steel made by Steen Neilsen (another really nice guy!) that was good fun!

Oh, some links

http://www.kniv.net/trond/English/Index.html

http://www.smie.no/engelsk.htm

I would add that my friends, Nemo and Fred Perrin really rate VG10 steel and they don't hold back either when using a knife!!! When I was chatting to Sal at this years IWA and Fred gave his demo of a balisong dance with the Spyderfly he really drove the point home how much he liked VG10 steel.

With reference to the Strider AR I was using the Bark River Highland Special, Farid custom and an Alan Wood Woodlore for comparison. The Strider was able to out chop all three blades. The Highland Special was a thinner blade (thus did not really have the weight to chop as well, though it was certainly very sharp!)and the other two were considerably thicker. I don't take the above as meaning much, only that a folding knife with a thickish blade in S30V was able to perform the duties of a smaller fixed blade without apparent problems.

The Bark River is A2 steel, the Farid is unknown but it is certainly a high grade tool steel, L6 has been suggested, though it is one of his early knives so who knows! The Alan Wood is o1 carbon.

I accept though that stainless steels are generally not as tough as carbon steels, just that with VG10 and S30V I have not had a single problem or concern. What more can I say? Perhaps Cliff you just are a lot harder on those poor blades than me! :p
 
The General said:
.... with VG10 and S30V I have not had a single problem or concern.
Click to expand...


Which stainless steels, in blades of similar geometry at similar price ranges have you had problems with in regards to durability during the same actions.

Thom, Fallkniven switched to laminates becuase they have a wider plastic region, they can bend them further before breaking. Generally this is at the cost of yield strength (they bend easier to the set point).

-Cliff
 
To me, toughness is defined as resistance to edge chipping and blade flexability (as opposed to breaking). Generally speaking, stainless blades exhibit poor performance in both regards when ground the same as a comparable carbon steel blade. I have seen some custom maker's get very good performance out of stainless however (Jerry Hossom comes to mind).

2 simple tests, hold a knife at the butt between your thumb and index finger and let it swing down and strike the edge (corner) of a hardened steel plate. If it is a "tough" steel, the edge should be either unharmed or slightly impacted. A "brittle" steel will most likely chip out. Jerry Hossom performs a similar test by driving a nail into a board and bending it about 45 degrees, he then tries chopping the nail which introduces the edge to a nasty side force. This usually results in a "blow out" on the edge.

The second test would be to simply place the knife in a heavy vice, employ a cheater bar and see how the blade fails (bend vs. break).
 
Thanks Mark, it's nice to hear firsthand reports on steels. Have you used S-7 since?
 
So am I to conclude that by toughness in a knife steel you mean it is easier to bend or indent rather than break or chip out,OK so that means that a tougher knife is a softer steel?A knife thats edge rolls easier means it is a better steel?Also why would an indented or rolled edge be necessarily better than a chipped edge?A chipped edge will continue to cut sometimes even more aggressively,where a rolled edge that has completely deformed loses its cutting ability entirely.Where is the advantage?I have been using exclusively,and hard a S30V Simonich Raven for 3 years now and have been very impressed with S30V and I dont like stainless steel that much.I have dug,skinned,fileted chopped and so on with no chips or edge rolling whatsoever.This even includes a chopping session on a 5 below zero backpack outing with no brittleness seen in the edge at all.This steel provided life saving wood for the night.S30V is a bit harder to sharpen but I have been more impressed with this steel than any other I have used.Just my opinion :)
 
The General said:
Funny how VG10 has proven to be superb in blades from Fallkniven in particular. Toughness never an issue.
Click to expand...

NOTE: "in blades from Fallkniven." Even a steel that is not optimized for toughness can be used to produce a tough blade, true? The all-VG10 A-1 I have is 1/4" thick with a convex edge. I would have to do something fairly nuts to damage such a slab of steel. As I recall, A-1's have been repeatedly stabbed into car bodies without more than cosmetic damage. (Cliff, of course, routinely does crazy things to perfectly innocent knives. :eek: )
 
wnease said:
Thanks Mark, it's nice to hear firsthand reports on steels. Have you used S-7 since?
Click to expand...


I have a couple of pieces that I am going to send to Roger Linger in a week or so. I need to take some pics and do some truely abusive test. I thought about it before but it is tough to do with the first one that I made. One of the ones that I sending to have heat treated I made with the intent to destory it. I would like to see someone who was really good at making knives do something nice with S7. I think that a skilled maker could do a unstoppable chopper in it. As it stand I hope to be able to at least give a little feedback on the steel itself in a few weeks. I want to try the nail cut that was described earlier any other thoughts on test?
 
The General,

Thanks for your clarification on the fixed blades. Still, I think that you're experiencing toughness due to thickness, versus the inherent toughness of the steel. With enough thickness, even SGPS and S90V at full hardness are tough, but that'd be a lot of extra steel required to make them tough.

Marsupial,

Toughness means that, at a given hardness, the steel is more likely to dent/deform than chip. So SR101 at Rc 60 is less likely to chip than S30V at Rc 60. Less likely to chip than S30V at Rc 57-58 for that matter.
 
My 2 cents on blade steels. We've been using 3V for all our blades. Some of the most important considerations for steels have been mentioned, proper heat treatment of each steel for each application, corrosion resistance, for blades; thickness for use and probably most important - edge geometry. When we started our edges were somewhat convex - that geometry will take a brutal beating. When moving to a 20 degree edge geometry the edge would still take alot of punishment. We tested against various wood; hard, soft, wet, dry, green, against various metals; copper, aluminum, galvanized water pipe, and even mild steels. Wood and soft metals didn't fracture the edge. Steel on steel something has to give, the 3V resisted fracturing and and proved to be amazingly ductile for steel H.T.'d to 61 Rc. We took that same test blade and clamped 2" of the blade tip on a block 6" high and forced the butt end of the handle down to the table - it held and returned with no ill effects. We also clamped the handle over a bench and dropped a 50 lb. piece of steel on to the blade tip - it shot off like a rocket without damaging the knife. The blade tip (2 inches) was clamped into a heavy vise and a 36" pipe wrench applied to the knife handle until the blade exploded (somewhere past 90 degrees). That testing was done on a Final Judgement blade.
There are many steel types ranging from realatively inexpensive to costly, each having varying ranges of use. We've been working with most all of them in the mold & die industry for over 25 years, Eric chose CPM 3V for his blades and has been pleased. There's alot of blades out there and many steels, Jerry's INFI is recognized for it's high quality, Warther museum (the famous carver Ernest Warther) is nearby us and I believe they still use "W" (water quench) steels for their specialized knife lines. Choose your poison, consider changing blade geometry as one thing that might work best for you. If your steel fractures to easily it was probably the heat treat process.

Enjoy your blades!
Jay Fehrman

John 14:6
 
Cliff Stamp said:
Which stainless steels, in blades of similar geometry at similar price ranges have you had problems with in regards to durability during the same actions.
-Cliff
Click to expand...

In similar price ranges and quality, I have not had any such problems.
 
marsupial said:
So am I to conclude that by toughness in a knife steel you mean it is easier to bend or indent rather than break or chip out
Click to expand...

A greater impact toughness means it takes more energy to cause brittle fracture, this means quite simply that you can hit it harder without it breaking. Greater ductility means you can bend it further without it ripping.

Yes, you can achieve both of these usually if you make the blade softer, thus an inherently tough steel has these qualities *at the same time* that it is also hard enough for high strength.



buttonpusher said:
The blade tip (2 inches) was clamped into a heavy vise and a 36" pipe wrench applied to the knife handle until the blade exploded (somewhere past 90 degrees).
Click to expand...

It suffered multiple breaks?

In regards to the 50 lbs weight impact, how high did you drop the weight from.

Which steels did you use which failed these tests?


The General said:
In similar price ranges and quality, I have not had any such problems.
Click to expand...


Thus no conclusion can be reached on the relative toughness as the failure points of none of the steels were seen.

-Cliff
 
So, it´s nothing really new here, isn´t it?

What i am really searching for is:

What can i expect of a steel? As Cliff said, stainless are strong because of the high alloy content.

But what is strong and what is not. Or: How many must a blade of, say .12" thick, flat grinded, 3.5" long made from 154CM, or the same made of S30V...take before it fails? What is minimum, depending on the steel grade?

So you can say, if that blade doesn´t take this it is a bad blade by itself, not by the steel grade.

Does anybody understand me?
 
Hmmm. I'm surprised that a small company like Busse could afford to arrange to have a specific type of steel smelted for their exclusive use. Are we sure INFI isn't a brand name like Carbon V rather than a type of steel? The economics of it just don't make sense to me.
 
Knife Outlet said:
Hmmm. I'm surprised that a small company like Busse could afford to arrange to have a specific type of steel smelted for their exclusive use. Are we sure INFI isn't a brand name like Carbon V rather than a type of steel? The economics of it just don't make sense to me.
Click to expand...

I´ve heard, INFI is a "designer-steel" made at the computer. But after i had the chance to read about a metallurgical research i think it is a cheap unclean steel loaded with anything you ever heard about as good alloy. Most components are so small, that they don´t have an effect on the steel. In general it is a .5%C and 8%Cr MoV a touch of W and some impurities like Cu. You might mention the other under .05% alloys but it´s much to boring to me.

The blades are more than .2" thick made of an .5%C steelHRC below 58, so it´s no surprise that they can be bend. I was more surprised of a Hill Knife, .2" thick, made from ATS34 HRC59 that bend without breaking under a side load of 500N.
 
You must log in or register to reply here.
Back
Top