Strider / Hinderer / Other "hard-use" mid-techs: Why S30V/S35VN?

[hardheart]

The side loading comment is the key I believe in that they aren't talking about impact here

Which is the weird thing, since they use an impact number to indicate performance against static loading. And of course the shape and size of the edge varies such an immense degree between knives. Even on the same knife, the profile and primary grind can cause the edge to be thicker at the tip than at the heel, if it has a high tip, no distal taper, etc.

 

[Ankerson]

Which is the weird thing, since they use an impact number to indicate performance against static loading. And of course the shape and size of the edge varies such an immense degree between knives. Even on the same knife, the profile and primary grind can cause the edge to be thicker at the tip than at the heel, if it has a high tip, no distal taper, etc.

Interesting huh?

 

[Gator97]

..I'll argue with just about anybody. Especially somebody who bursts in claiming he's "...sick to death of this ********."

That I am sure of I was just trying to make sure unsuspecting readers understood you correctly, otherwise it seemed like you had bigger prob with
"I'm sick..." statement(which does have its merit) than Crucible's very dubious document which gets misused(and I suspect it was designed for misuse)...

 

[Gator97]

That and I think we should point out that impact testing isn't the one and only holy grail of steel testing and or performance.

My point exactly. Impact in general isn't even main designed knife use. Still, there's a market for it and big knives in general used to describe those knives, which is why I think it's misleading.
On the other hand, high impact resistance can aid in edge holding with super hard/super thin edges too, in short, it'll never hurt to have extra impact resistance, 62-63HRC CPM 3V is a very good example of that.

 

[marcinek]

That I am sure of I was just trying to make sure unsuspecting readers understood you correctly, otherwise it seemed like you had bigger prob with
"I'm sick..." statement(which does have its merit) than Crucible's very dubious document which gets misused(and I suspect it was designed for misuse)...

There wasn't much in that original post that I didn't have a problem with.

I believe, however, you and I are in agreement in that anything somebody you haven't gotten to know (like, for me, Cliff Stamp) said should be viewed with a healthy bit of skepticism.

(And, of course, there are the people who you have gotten to know and are worthy of even more skepticism. And no, I'm not telling who I am talking about.)

 

[dingy]

How tough does it really have to be for folders and hunting knives, what we usually see it used in?

It's more than tough enough for those types of uses, and it holds an edge to boot.

Cutting..... Well that's what knives are supposed to be used for right?

I put a lot of pressure on those blades when I run my full battery of tests...

as i said above s30v is suited on small fix and folding knives , but not a choice for biger fix blades.
you use a lot of pressure on those blades , that is a way to test strengh , not toughness.

for making longer blades , the toughness is an important factor to be consider more than strengh.

i think the title or topic of this thread is "hard use "
do you have any expriences on larger blades made of S30V? or throwing a s30v knife as you stolen ?

like i said already , cutting test , no matter what pressure you pushed on , is not a way of testing toughness.

dingy

 

[Ankerson]

as i said above s30v is suited on small fix and folding knives , but not a choice for biger fix blades.
you use a lot of pressure on those blades , that is a way to test strengh , not toughness.

for making longer blades , the toughness is an important factor to be consider more than strengh.

i think the title or topic of this thread is "hard use "
do you have any expriences on larger blades made of S30V? or throwing a s30v knife as you stolen ?

like i said already , cutting test , no matter what pressure you pushed on , is not a way of testing toughness.

dingy

We are still talking about 3 to 4 inch folders here, hard use or not and in taking that into count S30V is more than tough enough.

That's going by the 1st post in the thread and the knives that he was talking about....

We aren't talking about swords and 10" + Choppers or jackhammer bits.

And yes I have had a few large Strider Fixed Blades go through my hands over the years and didn't notice any issues with them.

Yes Strider does produce larger fixed blades.

 

[OrdnanceBubbaUSMC]

Watched some "Russian Hard Use" tests on Spyderco's Military and Paramilitary last night...Military showed itself very well and prett much satisfies my individual view of folder blade toughness - assuming it is an ordinary specimen and not a softy. My Native FRN was no where near that tough in the edge and kept me from using it or original Patamilitary roughly. Maybe S30V treatment has developed or is hit or miss/difficult for consistency.

Most interesting in those vids, but not topic related (sorry), Paramilitary failed spine whacks which is not the first time I have seen it. Always took it for granted that it was a Tri-Ad/Axis level lock but doesn't really seem to be outside of static weight testing.

 

[eodtoad]

Forgot quote V

 

[eodtoad]

I defy you to define transverse and to then revisit your statement.

But to spell it out for you in painful detail crucible said:
"Although the longitudinal toughness for all three of these grades
is about 25-28 ft. lbs."

So then what are the transverse numbers?

"CPM S30V 10.0 ft. lbs.
154CM 2.5 ft. lbs.
440C 2.5 ft. lbs."

Pulled straight off the data sheet.

So, in case it wasn't painfully obvious, steel is non-homogeneous. Its grain structure affords it different properties on different axes.

In this case, according to Crucible, S30v has a transverse toughness that is roughly 1/3rd (note an anecdote was offered in lieu of data) of its longitudinal toughness.

So, again according to this datasheet, you'd need to orient the grain spine to edge to see this performance gain at the edge. NOBODY DOES THIS. (ok maybe someone does this, but I'm struggling to think of why.)

So while the given data suggests to users that S30v is "five times as tough," its only five times as tough on one axis and that axis will normally be oriented in such a way as to not produce the at-edge results users typically look for.

Thats what that means. Was that clear enough?

This data is not referring to grain structure, it's referring to downward force on a blade vs. lateral force on a blade. The data shows S30V to be about 4 times tougher than the other two.

 

[chiral.grolim]

This data is not referring to grain structure, it's referring to downward force on a blade vs. lateral force on a blade. The data shows S30V to be about 4 times tougher than the other two.

Older thread, but thought to mention that AFAIK those measurements weren't taken from a knife blade, i.e. there was no "spine" or "edge" to be had.

 

[eodtoad]

Older thread, but thought to mention that AFAIK those measurements weren't taken from a knife blade, i.e. there was no "spine" or "edge" to be had.

Isn't it the same idea though, stressing a rectangular shaped piece of steel? length versus width?

 

[chiral.grolim]

Isn't it the same idea though, stressing a rectangular shaped piece of steel? length versus width?

Length vs width do not enter the discussion, it is a question of how the test sample was taken. "Transverse" and "longitudinal" mean the same thing here as they would for cutting wood, implying the presence of steel "grains" which form as the metal is rolled into sheets. The PM process works to reduce the grain size, but it unfortunately does not eliminate it, as the Charpy Data shows.

"Transverse toughness" is resistance to impact between a collection of grains, getting them to separate, and is measured with samples cut such that the length runs across the grain (perpendicular).
"Longitudinal toughness" is resistance to impact along a collection of grains, breaking the grains themselves, and is measured with samples cut such that the length runs along the grain (parallel).

A knife-blank can be cut from a rolled sheet of steel such that the grain is parallel, perpendicular, diagonal etc. in relation to the length of the blade.
If the grain is oriented spine-to-edge (across the blade), a sufficiently powerful impact against blade edge or spine or side will snap the blade from spine to edge where it isn't thick enough to resist the blow, as this is where the weakness lies.
If the grain is oriented heel-to-tip (along the blade), a sufficiently powerful impact against blade edge or spine or side will snap the blade from heel-to-tip where it isn't thick enough to resist the blow, as this is where the weakness lies.

However, since most knife blades are wide, thin, and long and subjected to leverage from heel-to-tip, most makers are worried about them snapping in half from spine-to-edge, so they orient the grain parallel to the spine & edge. It's better to have grains tear out of the thin edge than have the blade break in half entirely.

 

[eodtoad]

Length vs width do not enter the discussion, it is a question of how the test sample was taken. "Transverse" and "longitudinal" mean the same thing here as they would for cutting wood, implying the presence of steel "grains" which form as the metal is rolled into sheets. The PM process works to reduce the grain size, but it unfortunately does not eliminate it, as the Charpy Data shows.

"Transverse toughness" is resistance to impact between a collection of grains, getting them to separate, and is measured with samples cut such that the length runs across the grain (perpendicular).
"Longitudinal toughness" is resistance to impact along a collection of grains, breaking the grains themselves, and is measured with samples cut such that the length runs along the grain (parallel).

A knife-blank can be cut from a rolled sheet of steel such that the grain is parallel, perpendicular, diagonal etc. in relation to the length of the blade.
If the grain is oriented spine-to-edge (across the blade), a sufficiently powerful impact against blade edge or spine or side will snap the blade from spine to edge where it isn't thick enough to resist the blow, as this is where the weakness lies.
If the grain is oriented heel-to-tip (along the blade), a sufficiently powerful impact against blade edge or spine or side will snap the blade from heel-to-tip where it isn't thick enough to resist the blow, as this is where the weakness lies.

However, since most knife blades are wide, thin, and long and subjected to leverage from heel-to-tip, most makers are worried about them snapping in half from spine-to-edge, so they orient the grain parallel to the spine & edge. It's better to have grains tear out of the thin edge than have the blade break in half entirely.

Ok, thanks. That makes perfect sense, like the grain structure in wood. I always laughed at the karate guys breaking short grain cut wooden boards. Thanks for the time to explain this in detail.

eodtoad

 

[fzla226]

Hard use is a misnomer for folders. if you want a knife for hard use get a carbon steel fixed blade and not a ti frame lock. Though the lock is the weaker link than the blade. It would likely bend out of shaoe before the blade broke.

 

[Jason B.]

Something I find funny and please correct me if I am wrong but...

Steel has grain boundary's which are multi-directional and the only way to see the "grain" of a steel is to polish, etch, and view under a microscope. Given that steel is a crystalline structure if it had a consistent grain in one direction, regardless of direction, it would be prone to failure. It's because the crystals are grouped in varying directions and separated by Grain Boundary's that a steel is strong in all directions.

Steel does not have wood like grain structure as implied in this thread. Which basically gives Zero value to the arguments made about it.

 

[AxisFan]

Steel can definitely have directional properties, mostly having to do with how it is processed - rolling & forging particularly. Perhaps not exactly like wood grain or to the same degree as wood, but that description got into common usage as an approximate way to describe the directional properties.

 

[MatthewSB]

Mike Stewart, of Bark River knives, said on his forum that the S35vn solved the chipping issues people were having with S30V and seemed very happy with it, calling it "...as close to A2 as stainless can get" or something similar.

I have a few very nice knives in S35VN that I'm hesitant to really wail on due to their high cost. I decided to buy a knife, made from S35VN, that I could enjoy thoroughly testing (comfortable handle, convex edge, etc.). My S35VN Bravo 1 should be here today. If, during normal camping use, anything goes wrong with the knife (all I'm really worried about is the edge) I can send it back to be fixed.

I'll be posting a review in the Outdoor Equipment section Sunday...

Since someone ressurected this thread, I should add that the S35VN Bravo 1 has been fantastic. I've beat on it pretty hard and no rolling, chipping, or rust

I will buy S35VN fixed blades with confidence.

 

[marthinus]

Something I find funny and please correct me if I am wrong but...

Steel has grain boundary's which are multi-directional and the only way to see the "grain" of a steel is to polish, etch, and view under a microscope. Given that steel is a crystalline structure if it had a consistent grain in one direction, regardless of direction, it would be prone to failure. It's because the crystals are grouped in varying directions and separated by Grain Boundary's that a steel is strong in all directions.

Steel does not have wood like grain structure as implied in this thread. Which basically gives Zero value to the arguments made about it.

I might be wrong as well, but I remember reading about sampling in Charpy Impact tests and how, Grain size, Heat treatment, Specimen orientation, Specimen thickness affect results.

Unfortunately in most steel data sheets available to us there is no specifications by many manufacturers and one is left with a few questions.

Here is an article about fracture toughness and orientation:

EducationResources, Community College, Materials, Mechanical, Fracture Toughness

Orientation
The fracture toughness of a material commonly varies with grain direction. Therefore, it is customary to specify specimen and crack orientations by an ordered pair of grain direction symbols. The first letter designates the grain direction normal to the crack plane. The second letter designates the grain direction parallel to the fracture plane. For flat sections of various products, e.g., plate, extrusions, forgings, etc., in which the three grain directions are designated (L) longitudinal, (T) transverse, and (S) short transverse, the six principal fracture path directions are: L-T, L-S, T-L, T-S, S-L and S-T.

From the book:

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

On Page 53

"The orientations of two Charpy impact bars are also shown.
Notice that in the transverse bar the elongated inclusions will run parallel to the base of
the V-notch while in the longitudinal bars they will run at right angles to the base of the
V-notch. Brittle failure occurs by cracks being opened up by the triaxial stresses
generated at the base of the V-notch. Now consider the
effects of the elongated inclusions. When the inclusions
lie parallel to the V-notch baseit is possible to have an
inclusion lying along the entire base of the V-notch. But
when the inclusions lie at rightangles to the base of the
V-notch an inclusion will pass the base of the notch at
only one point. Hence, the inclusions will enhance crack
formation much more effectively for the transverse bar
orientations where they lie parallel to the base of the V-
notch. Charpy data on rolled sheet containing
elongated sulfide inclusions give impact energies of
around 44 ft-lbs for longitudinal bars and only 15 ftlbs for transverse bars. The data provide dramatic
evidence illustrating how elongated inclusions
reduce the transverse toughness of wrought steels."


Another that seems to discuss orientation:
Suranaree University of Technology

• Longitudinal (B)
shows the
best energy absorption because
the crack propagation is across
the fibre alignment.

• Transverse (C)
gives the worst
energy absorption because the
crack propagates parallel to the
rolling direction