440V's brittleness?

Joined
Aug 11, 1999
Messages
1,111
I started a thread in Shoptalk re: 440V but figure I can get good feedback here, too. 440V offers great wear resistance but, “on paper,” trades-off quite a bit in toughness, to the point that it is even described as relatively “brittle.” I have been referred twice already to Crucible’s stats and bar graphs, etc; however, I have not found any confirmations of this brittleness in “real world” use. Therefore, perhaps some of you Starmate, Military, Native users can illustrate or animate the quantitative data w/your qualitative experiences?

Sal noted in an early October thread started by Jeff Clark that Spyderco lowered its 440V blades to 55/56 for an optimum combination of wear resistance and toughness. It’s a good thread (thanks for directing me, Jeff); to review, see

http://www.bladeforums.com/ubb/Forum20/HTML/001382.html

Jeff asked a question there that was never really answered: “What kind of failures would you get at higher rockwell? I would guess chipping and maybe tip breakage.” Yet he noted yesterday in Shoptalk that “the edge would roll when I used the Starmate to behead rabbits at the low rockwell.” Outlaw_Dogboy also experienced softness in the famous “staple incident” (!), although apparently his Native’s blade was an anomaly.

Jeff’s experience seems rather surprising in light of 440V’s reputed properties. (If it rolls at 55/56, is it really brittle at 57/58?) So let’s forget its stats on paper for a moment. At 55/56 RC, has YOUR 440V Spydie also experienced any similar rolling, or is it “just right”? For those possibly w/older models, has YOUR higher 57/58 RC 440V shown any chipping in moderate or hard use?

Similarly, Sal, if you have time to reply, I just want to reiterate Jeff’s October Q: what kinds of failure did you see in your 440V testing at higher RCs? In what kinds of tests? I’m simply puzzled at the discrepancy between its apparent brittleness on paper but the absence of any “real-world” experiences to confirm it. Is its brittleness possibly overstated or misunderstood?

Curious and puzzled,
Glen
 
Hey, O_D here....
The famous "staple incident". Yep, I would say that it rolled, not chipped. As far as anomalous... I don't know how anomalous it is. I sent it back to Spyderco. Sal wanted to check the hardness, and it came out to 55.5. Right on the money, pretty much.
No one ever really gave an explanation of what was going on. I swear it was just a magazine staple, though. So, I don't know about anomalous. In the absence of further testing, experience, or explanation, it would seem that 440V, at least in the BF Native and at the prescribed hardness, will roll, not chip (and not cut through), when applied to a magazine staple. Maybe cutting through (well, into, not through) a staple may be a little tough on a knife.
I'm reluctant to use my BF Native now, since it is such a nice knife. So, I went out and bought my first Military. I'll be sure to update people when/if I see similar occurrences with it. Meanwhile, a Spydie Standard has replaced the Native. I guess it's about time to tear through my magazine pile again. We'll see what happens.

------------------
It's just a ****ing staple!
Maybe we should make knife blades out of staples!
Outlaw_Dogboy, Pax River NAS, Republik of Marilundt


 
I chipped the blade on my BF Native. It was just a small chip nearer the point than the serations. I was cutting something and ran into a hardened peice of steel. I didn't think too much about it because I knew that the steel was there I just misjudged the length of it. I have chipped blades before doing the same thing, I know I should of learned the first time. It wasn't a very big chip and has almost come out with a little touching up on the on the new 204 brown sticks.

ALL steel will chip if abused. BUT a regular staple?!?!?



------------------
Dwight
Metro Atlanta Area

This post is a natural product.
The slight variations in spelling and grammar enhance its individual character and beauty and in no way are to be considered flaws or defects.


 
Signnnnn... My intentions to obtain a Military for personal use is closing in fast. But now how does one tell which rockwell Military is going to be shipped?? I feel this is a legitimate issue for those who intend to obtain one. Sal?

L8r,
Nakano
 
Fred Perrin reported on a tip breakage when he tested (hard use)and reviewed the Mil. He reprofiled the tip and no further problems - he still gave the Mil a double thumbs up.
 
Just for kicks and so OD wouldn't feel singled out, I tried two knives on some staples. In fact, I used a BF Native (440V) and a Buck 501 (BG-42, rc=61) on some staples holding a Camillus brochure together.

And just so there was no doubting how much abuse they were taking, I cut clean thru the staples with both knives (took some doing, pressed down on the staple using some cardboard on my desk as a backing).

Both knives developed small chips ... could've been rolls, but they looked like chips. Both were fixed with about twenty strokes on a DMT coarse hone. I didn't have a steel on me at the time or I could've tried re-aligning them if they were rolls ... but they were like really small dents.

The Buck had its factory edge at the time (about 25 degrees total included angle, measured with a laser pointer), so it was a fairly thin, and hence predictably vulnerable edge. I sharpened the Native several times before, but neglected to measure its angle, but it was wider than the Buck (and wider than my Calypso with its 31 degree angle).

Don't know if this test means much. I guess I just had time on my hands
smile.gif
... but staples seem fairly tough, and it may be an underestimation of edge strength to say when one doesn't hold up to a staple. I mean, it is hard steel wire ...

I don't have any other 440V blades to test on ... maybe the next time I'll take the Native's edge angle to 45 degrees (like my Benchmades) and see how the thicker edge holds up.

------------------
Longden Loo - Ventura, CA
Technology's the answer, what's the question?

 
Nakano 2, I would highly recommend going ahead and getting the Military. I really like the 440V, despite my profile signature
redface.gif
. I think I was asking too much of the 440V, based on the glowing praise for it from so many people. Obviously, as we may be seeing now, they weren't hitting metal staples with their 440V blades. After all, I don't think any knives are really designed to cut metal. Yeah, some may be able to do it, especially if they have a thick edge. But, one of the first things I ever learned from my dad about knives was Don't let the edge contact metal. It will dull it, and dull it quickly. Hmmm... I guess he was right.
The last thing that I want to do is discourage anyone from buying a 440V blade. The bottom line is, it will hold and edge about as good as ATS-34, the best I can figure. But, it will get much keener (my pet word for the day) than ATS-34 (or ATS-55), at least in my hands. It will get scary sharp, whereas I can only get ATS steels shaving sharp. The only steels that I have found so far that will get keener than the 440V is GIN-1 (doesn't hold an edge that long), M-2 (it will get scary sharp, and hold it as long long as the 440V, best I can tell; but hey, it stains quicker, or at least that's what I hear), and 1095 (I have a REKAT UNK that the hairs will leap off a persons arm when they see the blade even coming their way!). Of course, out of all of those, I think only the ATS-34 in a Benchmade edge has seen a staple. It held up better, but I think it was more the edge angle. No rolling or chipping. It just stopped shaving.
So, Nakano2, get the Military. I did, after my staple incident. And I don't regret it one bit.

------------------
It's just a ****ing staple!
Maybe we should make knife blades out of staples!
Outlaw_Dogboy, Pax River NAS, Republik of Marilundt


 
Nakano 2,
I believe any Military (or any Spydie 440V blade) out on the market now will be treated to 55-56 RC -- you can see Sal’s prior comments at the thread linked in my opening post. In the concurrent Shoptalk thread, Tom Mayo and Darrell Ralph (just about the most knowledgeable folks about the stuff) state that 440V remains extremely wear-resistant in the 56-58 range (much more so than well-treated ATS-34, D2, BG42, or other steels at higher RC, 59+). Interesting tangent: Tom Mayo stated yesterday (and before) that, when treated below 56 RC, 440V’s corrosion resistance “goes out the window” -- his words, paraphrasing Paul Bos. Hmm...?

Longden’s (new!) staple test appears to confirm 440V’s expected behavior, i.e., to chip slightly. Pyrguy’s experience w/chipping sounds similar (though could you elaborate on the “something” you were cutting and what the “hardened steel” was that you hit?
smile.gif
). I do agree w/O_D that staples are not as “wimpy” an “opponent” as we might think -- they are very hard and dense: what other everyday metals, in the size of a staple w/a chisel pt, can consistently get driven through 15 sheets of paper? (You might be able to chew through thicker wiring in your home or office, but you’ll likely chip your tooth on that “***ing staple”! But try at your own risk
smile.gif
)

But alongside those, O_D’s 55.5 RC Native DENTED rather than chipped. And Jeff Clark noted similarly that “the edge would roll when I used the Starmate to behead rabbits at the low rockwell [55/56].” Am I the only one confused by this wide-ranging behavior in a steel whose CPM processing is designed to diminish or eliminate such variability?!?

O_D,
Your and comparisons are very eye-opening, and go very much against the grain of 440V’s reputed properties on paper. Which is not to suggest you’re incorrect -- quite the opposite, it’s precisely the kind of perspective based on *experience* I’m asking about! No doubt differing blade geometries play into this; however, 440V is supposed to offer extremely high wear resistance w/a keen edge (and no denting/rolling!) even in a very thin blade -- one of its reputed advantages. I mean, ON PAPER (!), 440V at 56 RC is supposed to keep a razor edge long, LONG after D2 at 59 RC has turned into a doorknob.

... But as the case may be from time to time, real world use can challenge or qualify a steel’s expected, on-paper characteristics. So do O_D’s comparisons square with other users’ experiences? How does your 440V stack up vis-à-vis the more familiar stainless and tool steels you have? (I’m particularly curious about 440V vs D2...)

Glen
 
But alongside those, O_D’s 55.5 RC Native DENTED rather than chipped.

I'll point out that I cut thru the staple whereas O_D merely ran the edge into it. I put significantly more stress on the edge, and while I had a visible dent, it's not confirmed that it's a chip vs a really deep dent.

No doubt differing blade geometries play into this; however, 440V is supposed to offer extremely high wear resistance w/a keen edge (and no denting/rolling!) even in a very thin blade -- one of its reputed advantages

I'm not sure about the claim for simultaneous high wear AND dent resistance. I seem to recall threads discussing 440Vs wear resistance and toughness see-sawing depending on the RC used. I don't recall an RC where you got both qualities. Of course I may have missed more than a few of these threads.

Doggone it, where's Cliff
smile.gif
?

I don't have a D2 blade or else I'd oblige you with a staple test.
 
Longden :

where's Cliff

Gathering data, I should have the results on some staple cutting shortly. Jeff Clark pointed out to me months ago this would be a reasonable standard, I agreed but just never got around to it.

-Cliff
 
Cliff, that's good to hear. A staple test should warm the cockles of O_D's heart
smile.gif


Dom, yes I used a cheap $12 POS laser pointer per a method I discussed in the general forum a while back:
http://www.bladeforums.com/ubb/Forum32/HTML/000926.html

Never had a chance to calibrate my results, so while I'm reasonably confident in the measurements, I can't vouch for them till I get someway to validate it.

Essentially, you plunge the blade midway into an inverted cardboard box, edge facing you. Aim the laser pointer at the edge near where it meets the box, such that the shadow of the spine is symmetric behind the blade, that means the beam is roughly in the same plane as the blade.

Now tilt the beam downward slightly so that you get a beam deflection on either side of the blade showing clearly on the box, and use your free hand to mark the outer most fringe of light on both sides of the blade. The deflected light will be a crisp line or a fuzzy one depending on whether the edge bevel is flat and uniform or if it's curved/convex.

Now turn off the laser and pull out the blade, and use a ruler to connect the two marks with the incision left by the blade at the point of the incision closest to you.

The drawn angle should be double the included angle of the edge (ie, 60 degrees if the edge angle is 30 degrees).

------------------
Longden Loo - Ventura, CA
Technology's the answer, what's the question?

 
Little claw,

Longden did his measurements with a POS laser pointer. Try this: lay a sheet of white paper on a cardboard box. Stick knife to about 1/2 blade length depth into box through paper. Lay pointer on box aimed edge-on to the blade so that the laser beam is bisected and reflects to opposite sides of the edge. Prop up the back end of the laser slightly to angle the beam down slightly. You want the reflected beams to be visible on the paper. Mark the beams with a pencil. Measure with protractor (or use a ruler and a little trigonometry).

You won't be able to see reflections off a sloppy or convex edge. Turn the lights off. Longden is the only one I know who's done it so far.


[This message has been edited by Jeff Clark (edited 10 December 1999).]
 
Regarding 440V - There is not much history. As with most of what we do.

We found that at 57/58, it was too hard. So far 55/56 is working well. Take a Military out into the field. Use it!

So far, it's been the best we've used for overall doing of the job of being a knife. I've chopped and hackied the serrated edge of my Military on rock hard woods with no damage.

We are the first at using 440V in production and we've only been doing it for a short while.

What production heavy duty dependable folder would you compare it with? use for use, mud, heat, cold, extreme conditions, gloves? Jeff Randall used a Military for a while in the bush. He indicated that it performed well.

I would guess the edge on OD's Native was too thin. They are not coming back for repairs on damaged blades. We get way more "goods" than "don't likes". Time will tell.

sal
 
I wonder if Spyderco is shipping the 440V Militaries with a different edge angle than other models to alleviate the problems with a thin edge?

Jeff: that was a great job of describing my process.
You won't be able to see reflections off a sloppy or convex edge. Turn the lights off. Longden is the only one I know who's done it so far.

Right, it especially works well on a NIB factory edge where the bevel is uniform, but even with a sloppy or convex edge, if you mark the outermost lines of light you'll get at least a rough measure.

As to being the only one to do this .... sheeyut! I can't be the only one with a cheap laser pointer and an interest in edge angles
smile.gif
I figured someone else by now would've shot down my method if it were seriously flawed. Maybe someone with access to precision measuring equipment can validate the method one of these days.
 
I've never had any trouble with my 440V blades. My Military has never been babied and still going strong. Now that I have a Starmate I can't wait to use it.
 
Hoooo-eeee... I feel like I'm really looking a gift horse in the mouth, every time I join in these threads discussing 440V. Let me just set the record straight, once and for all: I have liked, and continue to like, the overall performance of my BladeForums Native with the 440V just like it is. Caveat: Notice that I did say "overall performance". For an explanation of overall performance, please see my last post on this matter, above in this thread.
FWIW, I believe as Sal stated above that the edge angle on my BF Native is just too thin. At least for staples. Works great on wood, paper, cardboard, etc.

Let me add some fuel to the fire, probably supporting the 'too thin' speculation
smile.gif
. This weekend was recycling day at the... O-D household
wink.gif
. Recycling day consists of gathering all the recycleables to take to the center, which includes, especially this weekend, a lot of cardboard. In times past, I have used the BF Native to cut up the cardboard. (Guess I should have talked about this before
redface.gif
, but better now than then probably). It would do a good job; however, by the end of the session it would start to drag a little in the cardboard, so that it would roll it a little. If I gave it a little 'saw' to get it through that, it would then eat go on through.

Well, this time, I used my Nimravus Cub in M2, and my Military. Sorry I had to split the chores, guys, but I wanted to give both a workout. Plus, there was more cardboard to cut this time than I have ever had, and I think there was enough to work out both. Well, at the end of the session, both knives were still shaving easily. I had thinned the edge of the 145 out quite a bit several weeks ago, to try to get a keener
wink.gif
edge on it, which I had. The Military had the factory edge on it, and OBTW it is a plain edge. Subjectively, IMO the Military (and the 145) did significantly better working through the cardboard than the Native did, and both had maintained their edges better at the end. I still haven't resharpened either of them, as I just don't think they need it. This morning the Military ate through a tree branch about a half inch thick with one well place chop. I was shocked and impressed.

So, I don't know if that really adds anything, reading back through it now. I am quite a bit more impressed with the performance of the 440V in the Military than I have been in the Native. And, I notice that the Military that Sal refers to is a serrated version. That can have a significant effect on the perception of the edge holding of 440V, to say the least. I think that one of these days, I'm gonna have to add yet another Military to my collection... one with teeth!
biggrin.gif


------------------
It's just a ****ing staple!
Maybe we should make knife blades out of staples!
Outlaw_Dogboy, Pax River NAS, Republik of Marilundt




[This message has been edited by Outlaw_Dogboy (edited 13 December 1999).]
 
O_D, very interesting results.

In the Native's defense (performance wise) against the Military in cutting cardboard, you may also have to consider blade geometry.

If both knives were comparably dulled (I mean that the edges themselves were similarly rounded) I'd expect the Native to have a harder time slicing thru a piece of cardboard due to the shape of the blade cross-section.

According to the Knife Center of the Internet specs on blade thickness, the Native is 1/8" (hollow ground spearpoint) and the Military is a thicker 5/32" (flat ground).

Assuming the blade widths (measured from edge to spine at the widest point) were the same (about 1") note that the Native reaches its full thickness halfway thru acoss the width, compared to the Military which doesn't do so till the spine.

The Native geometry thus presents a full 1/8" profile (thickness-wise) to the object being cut at only 1/2" thru the width of the blade, which would equate to geometry similar to a fully flat ground 1" blade of 1/4" thickness at the spine ... far thicker than the Military.

I would expect the effect to be somewhat like an edge with a very thick primary bevel.

If you're trying to test the effects of wear from cutting similar amounts of cardboard, you may have to evaluate the resulting cutting edges by cutting test material without going across the width of the blade (ie, holding the knives at an angle and cutting using maybe only the front 1/4" of the blade, or cutting 1/4" rope). It may turn out that both are actually comparable in dullness ... just a wild guess
smile.gif


------------------
Longden Loo - Ventura, CA
Technology's the answer, what's the question?

 
OK, now I think you've totally lost me
frown.gif
. Does what you said equate to better or worse (or thicker or thinner, not necessarily respectively) edge geometry (with better being the geometry that supports the edge better to keep it from rolling)? Or did I miss the point entirely? I think it has been too long a day...
frown.gif
.


------------------
It's just a ****ing staple!
Maybe we should make knife blades out of staples!
Outlaw_Dogboy, Pax River NAS, Republik of Marilundt


 
Back
Top