INFI vs SR-3V

[ace]

The article doesnt expound on different steels- only different hardnesses.
Maybe you are mixing it up with some other article

Notice how the article doesn't specify the steel it talks about because the concept is relevant to all steels we are interested in. From the article:

 

[tsiloics]

Based on 20+ years of buying/using/sharpening Busse knives, I'm very happy with INFI in larger blades, and also think it has a lot to offer in mid-sized and even smaller blades. For me, I think modern 3V at 60+ gives INFI a serious run for its money in mid-size blades.

I would not expect Busse to offer models in multiple steels, rather I think they would choose a steel for each model based on overall characteristics. Although it would be awesome to see something like the NFCM offered in both steels and heat treats. That would be a fun test.

 

[Gravelface]

Buy what you love and love what you buy.

Jerry has done incredible things with whatever steels he’s used over the years. His A2 are still some of my favorite users. The SHBMs, they stand on their own, Fehrman did a great job on 3V for years till Carothers brought it to a new level. Siegle as well has 5160 competing with the best of the super steels…..

They have an understanding of their product that the rest of us speculate on and argue about aspects for pages upon pages. But truth is any of these knives will perform incredibly for years / decades without issues. The only complaints are these tards intentionally trying to break blades to prove what?! And believing their ability to break a knife shows some flaw and their input would make a better product.

There’s a reason their names are on the company and we are the consumers. With so many makers out there, find the ones that suit your needs and stick with them.

 

[beachmaster]

Notice how the article doesn't specify the steel it talks about because the concept is relevant to all steels we are interested in. From the article:

View attachment 2527946

Yes- no matter which steel you use the hardness doesnt change stiffness.
That doesnt mean that choosing an entirely different steel wont.
"Since steel is primarily iron it is controlled by the strength of the iron- iron bonds"

As i mentioned before this SHOULD very clearly contradict your point as obviously different steels have different compositions ergo different amounts of iron ergo different iron- iron relationships.

You are reading into the article something that is opposite of what is there.

 

[PeteyTwoPointOne]

Buy what you love and love what you buy.

Jerry has done incredible things with whatever steels he’s used over the years. His A2 are still some of my favorite users. The SHBMs, they stand on their own, Fehrman did a great job on 3V for years till Carothers brought it to a new level. Siegle as well has 5160 competing with the best of the super steels…..

They have an understanding of their product that the rest of us speculate on and argue about aspects for pages upon pages. But truth is any of these knives will perform incredibly for years / decades without issues. The only complaints are these tards intentionally trying to break blades to prove what?! And believing their ability to break a knife shows some flaw and their input would make a better product.

There’s a reason their names are on the company and we are the consumers. With so many makers out there, find the ones that suit your needs and stick with them.

Well said!

Don't forget about Dozier & D2

 

[Private Klink]

Nicely stated Jason.

 

[DeadboxHero]

Yes- no matter which steel you use the hardness doesnt change stiffness.
That doesnt mean that choosing an entirely different steel wont.
"Since steel is primarily iron it is controlled by the strength of the iron- iron bonds"

As i mentioned before this SHOULD very clearly contradict your point as obviously different steels have different compositions ergo different amounts of iron ergo different iron- iron relationships.

You are reading into the article something that is opposite of what is there.

Ergo, show me a 0.250" thick, 4" long flexible knife.

 

[beachmaster]

Ergo, show me a 0.250" thick, 4" long flexible knife.

Nobody is arguing that geometry doeant affect flexibility but for 1/4 we are speaking of stiff and more stiff lol

 

[TheTip]

This doesn't make sense to me. How steels work is not really open for discussion, the article explains why different steels have same stiffness. I am really at a loss here. The information is available do with it what you like.

I've just realized that there is still something that hardness has to say, when it comes to stiffness and break resistance on lateral bending. If there wasn't, then I can't understand why the European thin swords (also named rapier) were standardly heat treated to a HRC in the 40 range rather than higher and katanas that had edges of +60 HRC needed to have differential HT with a spine in the 40+ range. Also why we cannot see springs that are heat treated to 60+ HRC in any industry? I am mixing things probably... I'm not a metalurgist, but I think the above arguments bring something in here.

 

[Nathan the Machinist]

Within the realm of steels used in knife production, the difference between the most flexible steel and the stiffest steel amounts to little more than a rounding error. For all intents and purposes the modulus of elasticity of steel is roughly 30 million psi. There are some very slight differences from alloying but you would never be able to tell the difference. Stiffness is also almost completely unaffected by hardness and heat treat. For all practical purposes, the stiffness is based on the geometry only.

If you take a rectilinear beam and double its width, it will be twice as stiff. If you double it's thickness it will be eight times stiffer. ←That's really all you need to know.


Springs are not normally especially hard. But it is not the heat treat of the spring that makes it springy, it is the geometry. The hardness of the spring is selected so that, within the intended range of use of the spring it's elastic limit will not be exceeded. There is no purpose to going harder and a harder spring will have a shorter fatigue limit and a more drastic failure mode. The purpose of a spring temper has no effect on its "springiness".

 

[Cobalt]

Within the realm of steels used in knife production, the difference between the most flexible steel and the stiffest steel amounts to little more than a rounding error. For all intents and purposes the modulus of elasticity of steel is roughly 30 million psi. There are some very slight differences from alloying but you would never be able to tell the difference. Stiffness is also almost completely unaffected by hardness and heat treat. For all practical purposes, the stiffness is based on the geometry only.

If you take a rectilinear beam and double its width, it will be twice as stiff. If you double it's thickness it will be eight times stiffer. ←That's really all you need to know.


Springs are not normally especially hard. But it is not the heat treat of the spring that makes it springy, it is the geometry. The hardness of the spring is selected so that, within the intended range of use of the spring it's elastic limit will not be exceeded. There is no purpose to going harder and a harder spring will have a shorter fatigue limit and a more drastic failure mode. The purpose of a spring temper has no effect on its "springiness".

While everything you have stated as well as others and metallurgists is true, it is misleading. I will try to explain in more depth. The fallacy being passed on by some metallurgists in the knife world is that regardless of HT all knives of the same cross section will behave the same laterally.
I will repeat myself again. This is only true for the ELASTIC range and under the yield point. The HT of all steels will affect the yield strength and will affect the behavior of the steel as it reaches and passes that point. So what this means is that if you have steel A with HT delta and steel B with HT crapola, and steel A's Yield strength is 270Ksi and Steel B's yield strength is 190Ksi, that means that when Steel B fails at 30 degree bend point at 200ksi, steel A is still holding that load and not failing. My example is an exaggeration to make the point. Once steel A passes it's yield point, the force required to hold drops because the steel has failed, and either permanent bending occurs or fracture occurs. So a steel with a higher yield strength will have a larger elastic range with the same slope because the slope of the curve shows that both steels behave the same until that yield point.

So to say that all knives of one type of geometry behave the same is simply not true. The behave the same to a point, then once that point is reached and my knife fails and bends or breaks, yours may keep going well beyond that point.

 

[Nathan the Machinist]

Oh yeah. Once you exceed the elastic limit, and are in the plastic deformation range, there's definitely going to be a difference between knives with different heat treats. Knives with a higher yield point (as a rule, harder) will continue to increase force as it goes up the stress strain curve (it is basically a line in this range, steel is a linear elastic material), and knives that are actually taking a permanent set will yield.

I didn't realize that was the argument being made.

Most people don't use their knives like that. But, yeah.

 

[Nathan the Machinist]

I think the point that the well intentioned metallurgist was probably trying to make is that you're not going to be able to change the feel of the knife in use (it's springiness) through alloy or heat treat. It is a function of geometry until you're actually breaking it. If you want a design to be more flexible, you either have to change the design or change the material. Titanium for example is about half as stiff as steel.

 

[Nathan the Machinist]

A lot of people don't realize that. It is a very common misconception.

For example, the president of an engineering firm I once worked at thought that changing the alloy on the roll cage on his race car to chromoly steel was going to make the car handle better because it would be stiffer. He was under the misimpression that the harder stronger alloy would affect the resiliency and handling characteristics of the car. This was a Penn State graduate and an intelligent person with an engineering degree. And he didn't know it either. It's a very common misconception.

 

[Ironic]

I nominate Cobalt and Nathan to the Steel Destruction Test Review Committee. Thanks, guys.

 

[beachmaster]

Within the realm of steels used in knife production, the difference between the most flexible steel and the stiffest steel amounts to little more than a rounding error. For all intents and purposes the modulus of elasticity of steel is roughly 30 million psi. There are some very slight differences from alloying but you would never be able to tell the difference. Stiffness is also almost completely unaffected by hardness and heat treat. For all practical purposes, the stiffness is based on the geometry only.

If you take a rectilinear beam and double its width, it will be twice as stiff. If you double it's thickness it will be eight times stiffer. ←That's really all you need to know.


Springs are not normally especially hard. But it is not the heat treat of the spring that makes it springy, it is the geometry. The hardness of the spring is selected so that, within the intended range of use of the spring it's elastic limit will not be exceeded. There is no purpose to going harder and a harder spring will have a shorter fatigue limit and a more drastic failure mode. The purpose of a spring temper has no effect on its "springiness".

There is a nearly 10% difference across steel types.

1% is a rounding error. This is not.

With differences this great a change in steel and a change in edge geo of less than .005 could change a knifes stiffness so significantly that even the layman would notice.

I can notice differences in steel while batoning, and unlike most users i have knives that are entirely identical in all but steel.

 

[Nathan the Machinist]

I can notice differences in steel while batoning, and unlike most users i have knives that are entirely identical in all but steel.

There is, in fact, about a 10% difference in stiffness from D2 on one extreme to S7 on the other extreme. Not large, but certainly more than an actual rounding error.

I'm curious, of the knives that you baton with. What are those alloys and what is the difference in stiffness in those alloys? I would be curious to know how small of a difference in stiffness would be perceptible to a person. If you can feel that difference, that's pretty incredible. It would be an interesting experiment to remove the steel markings off of the knives and make them visibly identical and then duplicate your batoning experiment and see if you can determine which steel is which based on a few percentage difference in stiffness. Which would also amount to a few thousandths of an inch difference in thickness and could be a normal manufacturing variability.

It is my opinion that, to say that it amounts to a rounding error when discussing whether or not steel and heat treat are what dictate a knife's feel rather than its geometry, is essentially accurate. But if you disagree, that's okay.

 

[beachmaster]

There is, in fact, about a 10% difference in stiffness from D2 on one extreme to S7 on the other extreme. Not large, but certainly more than an actual rounding error.

I'm curious, of the knives that you baton with. What are those alloys and what is the difference in stiffness in those alloys? I would be curious to know how small of a difference in stiffness would be perceptible to a person. If you can feel that difference, that's pretty incredible. It would be an interesting experiment to remove the steel markings off of the knives and make them visibly identical and then duplicate your batoning experiment and see if you can determine which steel is which based on a few percentage difference in stiffness. Which would also amount to a few thousandths of an inch difference in thickness and could be a normal manufacturing variability.

It is my opinion that, to say that it amounts to a rounding error when discussing whether or not steel and heat treat are what dictate a knife's feel rather than its geometry, is essentially accurate. But if you disagree, that's okay.

So first maybe to clarify a bit my flagship knife is .5" tall, .021" bte, .128" thickness and ffg so in that blade a difference in stiffness is more noticable than in a bigger chopper or something. I am working with a massive variety of steels but primarily right now 1v, s35vn, a2, and some baker forge san mai.

Stiffness may be a rounding error for your average knife guy, 95% of whom are collectors, and ever the harder use guys who use their knives, maybe for some chopping and skinning.

I do a lot of splitting- for my reviews its not uncommon to sit with a massive baton and a knotted twisted piece of wood for an hour. When knives are so slowly bending and twisting you get a feel for stiffness after the thousandth time.

*shown is not my general massive baton- using a normal baton is such a waste of energy

 

[Nathan the Machinist]

There are an awful lot of variables there that are uncontrolled, particularly the timber. I think it's probable that the difference in stiffness maybe imagined. A lot of those steels are going to be practically the same. The size of that variable compared to the others variables that may be present, particularly the organic nature of the knots themselves, makes me wonder if perhaps this is something that is imagined and not actually real. If it's real it can be predicted and repeated. Perhaps decide which knives you think are most flexible and most stiff and then look at their Young's modulus and see if your impression is accurate.

Regardless, I did not intend to come on to this forum and engage in the discussion, I'm swimming in somebody else's pool here so I will show myself out. Peace.

 

[TheTip]

Nathan the Machinist Are you that guy from youtube who chops a steel cube with a knife made by a company wearing his name? Are you Nathan Carothers himself (or just a fan who wears this nickname in sign of admiration for the real Nathan Carothers)?