A medium bounds for performance : chopping

[Cliff Stamp]

To continue the discussion on performance :

http://www.bladeforums.com/forums/showthread.php?t=492898

How about the expected performance of a 14" Fiskars Hatchet? How much wood should be chopped (1-2 year seasoned spruce, juniper, pine) before the edge just stops shaving? Answer :



Seven hundred sixty four chops. At this point I had to exert enough force and a draw to shave that it was difficult to do without cutting my skin, so I would judge the shaving ability effectively removed. Now of course you would want to repeat this a few times to get a feel for the uncertainty, and of course shaving is fairly subjective, and wood changes, etc.

But, my question remains, if this cheap hatchet, with a production heat treatment on no special steel, not friction forged, not CPM, not even guaranteed to be a tool steel, can make almost a thousand chops into 1-2 year seasoned spruce, birch and juniper, what is reasonable to expect from a "high end" knife/hatchet costing 5-10X as much?

Note this hatchet has been reground (see the review for details) and before this chopping was brought up to a polish of the ultra fine Spyderco benchstone and was push shaving readily, push cut newsprint at 1"+.

-Cliff

 

[the possum]

I'm posting if for no other reason than to hopefully get more people to see it. But still, you bring up a valid point. What should you expect from "better" blades? (Guess I won't limit this just to hatchets/axes)

Looks to me like even a cheap blade can reasonably handle the easy tasks. And wear resistance isn't much of an issue if you're just chopping clear wood. Once again this confirms my experience in that regard. I don't see wear resistance as any advantage on chopping tools. Even after over 700 chops, it sounds like that edge could be brought back in just a couple seconds with a few swipes on a stone. What's the big deal?

Here's where I like to focus- the hard stuff. Is the steel hard and strong enough to resist rippling and denting when hacking through serious knots? What if ya discover a nail in that wood, or accidentally hit a rock? How bad does it take the damage? Does it have enough impact resistance to prevent chipping even at high enough hardness that's needed for the strength? I haven't really chopped a whole lot of wood with my Wetterlings hatchet, but I've had to sharpen it several times just from the edge banging into stuff rolling around in my trunk.

Also, if we want to talk about chopping blades- big knives, machetes, goloks, khuks, etc., then I put a good deal of emphasis on balance. This is one of those features that can easily make a big difference in how well the tool works, yet is seriously lacking in most production blades. (And I may hang myself with this comment, but the same can be said about lots of custom blades I've handled.) This is something I'd expect to be addressed if I was looking to spend money on a "better" tool.

 

[Elen]

Well, I doubt many knives, expensive or not, would be as good at chopping wood than that Fiskars. Which model is it, the Handy 600, about 520 grams, maybe? Fiskars has been making tools for over three hundred years. They know what they're doing, and that thing is designed to chop, not cut. From a more expensive hatchet, you can of course expect more, but are unlikely to get much more, I can tell you that. From a knife - well, I wouldn't.

 

[the possum]

Elen-
I didn't really get the impression Cliff was trying to compare the chopping ability of a cheap hatchet vs. a knife. I think he was getting at general trends about edge holding. If a modestly priced tool made from no-name steel can do a lot of work, how much more would you reasonably expect from a better made and more expesive tool of a similar type? If the cheaper tool (whether knife or hatchet) can get the job done under ideal conditions, under what circumstances would you expect the better quality tool to perform better?

 

[Cliff Stamp]

What should you expect from "better" blades?

Much better edge retention and the ability to take a finer profile without damage. However the edge on this Fiskars is already very acute, 10 degrees per side tapering to 12 degrees in the final sweep under 0.030", microbevel at 15 degrees.

And wear resistance isn't much of an issue if you're just chopping clear wood.

Yes, I just checked this again, 850 chops this time and again it would be difficult to shave without cutting the skin. This kind of makes it absurd to argue about the need for lots of carbides in chopping tools, as of course it was EVER the case that axes had such steels.

Even after over 700 chops, it sounds like that edge could be brought back in just a couple seconds with a few swipes on a stone.

Two passes right into a Spyderco medium to grind off all weakened metal. 10 per side on the medium, 10 per side on the fine, 10 perside on the ultra fine, edge restored to push shaving sharpness.

Is the steel hard and strong enough to resist rippling and denting when hacking through serious knots?

Yes, no clear woods here.

What if ya discover a nail in that wood, or accidentally hit a rock? How bad does it take the damage?

This is a 3.5" concrete nail, 12 hits with a 26 oz framing hammer to cut directly through. No damage to the edge of the hatchet. While there are makers who advocate this test, Hossom for one, this is more of a sideshow event because as long as you do it carefully it is no problem for any knife. I have done it with A. G. Russell Deerhunters (0.010"/10 degrees) so it is a joke for anything with a significant edge profile.



This however is a different story. Another of the same nails driven into a 2x4 and then the hatchet attempts to cut right through it. The nail of course just moves under the impact and exerts horrible lateral forces on the edge. The impacts from the axe cut from 1/4 to 1/3 of the way through the nail. I also chopped several times into a concrete block, that did nothing compared to the nail, nor would it be expected to as it is fairly soft and shatters easily, it is only a concern if it has a lot of big chucks of rock.



That is the edge after all the utility work. The larger damage points are of course the nail in 2x4 impacts. The concrete flattened the edge back to about 0.010", the nail caused damage up to 0.020" thick on the fiskars bit. Note again that the angle of the bit was 12 degrees per side in this region.

Does it have enough impact resistance to prevent chipping even at high enough hardness that's needed for the strength?

There was significant deformation which raises the question as could the hardness be higher - yes, but then it would not be able to be filed which tends to be a big negative for axe owners. There was little direct fracture which was good, the edge tended to deform. Now here is the critical question, how many "high end" knives will the corrosponding makers/manufacturers advocate to take less damage on such work (with a similar edge configuration).

Note that since the damage was constrained to a depth of 0.020", this would put it inside the edge bevel of most large knives and quite frankly I would recommend at more obtuse bevel for that type of work. With a standard tactical edge of 20 per side you are likely to notice nothing even when blasting the edge into the nail because the edge would be 10 times stiffer at that profile than the one that it currently has applied.

-Cliff

 

[Cliff Stamp]

Well, I doubt many knives, expensive or not, would be as good at chopping wood than that Fiskars.

This chops woods about as well as a decent 10" bowie, but I have had it significantly reground as noted in the review. Before that, it would be outchopped significantly by a decent large knife. That however was not the point I was trying to make, I was talking about edge retention more so than the raw chopping ability.

If a modestly priced tool made from no-name steel can do a lot of work, how much more would you reasonably expect from a better made and more expesive tool of a similar type?

Yes, now how for example would one of the $300-$500 custom hatchets perform at the above work, wood as well as nail/rock impacts?

-Cliff

 

[Cliff Stamp]

Background details :

http://www.cutleryscience.com/reviews/fiskars_hatchet.html

Note the steel specification of 50-56 HRC at the edge, thus a decetn custom could be expect to be about 5-7 points harder and see significantly reduced deformation.

-Cliff

 

[hollowdweller]

Hey Cliff!

Great post. I'd be interested in knowing if you had ever tried this with a GB Wildlife and how did it compare to the cheaper one???:thumbup:

 

[the possum]

Cliff-
I wasn't actually asking you those questions in regards to this specific hatchet. I was posing questions to the readers at large. But thanks for the info, all the same.

 

[Elen]

This chops woods about as well as a decent 10" bowie, but I have had it significantly reground as noted in the review. Before that, it would be outchopped significantly by a decent large knife. That however was not the point I was trying to make, I was talking about edge retention more so than the raw chopping ability.

Yes, now how for example would one of the $300-$500 custom hatchets perform at the above work, wood as well as nail/rock impacts?

Most knives ain't 10 inch.

Would be interesting to see how well a 300 dollar custom hatchet does. Somehow I expect it won't do ten times better than this 30 $ Fiskars.

 

[Jerry Hossom]

This is a 3.5" concrete nail, 12 hits with a 26 oz framing hammer to cut directly through. No damage to the edge of the hatchet. While there are makers who advocate this test, Hossom for one, this is more of a sideshow event because as long as you do it carefully it is no problem for any knife. I have done it with A. G. Russell Deerhunters (0.010"/10 degrees) so it is a joke for anything with a significant edge profile.

The test I recommend is a single cut through an 8d common bright nail (Home Depot) - not as easy to be "careful". Please try to be accurate when you quote or reference me, Cliff. It helps avoid unnecessary conflicts, joking or not joking. Thanks.

Cutting a nail driven into wood then bent 45 degrees is a great cutting test and does indeed apply huge lateral force to the edge. It's a test that Rob Simonich and I used to test S30V when it was first available. I've used it on nearly every steel I've ever used.

 

[Cliff Stamp]

I'd be interested in knowing if you had ever tried this with a GB Wildlife and how did it compare to the cheaper one?

No I have not, the Bruks is much harder and thus should resist deformation more, however grinding back the edge on the Bruks to even remove 0.010" of damage is not a trivial task. If it ever does get damaged when I lend it out to a friend I'll repeat some of the above work as I will have to regrind it then anyway.

Most knives ain't 10 inch.

True, most axes are not this small either. Initially the Fiskars would chop about as well as a high class 7" blade on medium thickness woods.

Would be interesting to see how well a 300 dollar custom hatchet does. Somehow I expect it won't do ten times better than this 30 $ Fiskars.

Given the steels that many favor, they are likely to do less. But at best I would be surprised if the damaged could be halved with a similar profile. I would be curious if something like L6 at 66 HRC would have enough impact toughness not to chip. That would be the only way to really reduce the deformation significantly.

The test I recommend is a single cut through an 8d common bright nail ...

Assuming this is a perpendicular cut, then the same commentary applies. It is a sideshow event as it doesn't correlate to actual impacts in use. It looks cool to some, but will be absurd to anyone who have used knives significantly. I noticed this right away with I did it years ago because it did not effect the blades the same way that it did when I had hit them while actually using the knives and hitting nails accidently in scrap or spiked wood.

As well, with any piece of stock work performed by an individual, you will quickly get very skilled at it. The first few times I cut up 3.5" nails with knives quasi-statically I had a bit of trouble keeping the edges free of damage, but after a few nails I had the process figured out and it was of no concern to do it with very thin blades. Thus it was again obvious that this was not a sensible test of durability because I could do it with almost anything and thus the "pass" rating was meaningless, everyone gets an "A" effectively.

In a similar note regarding chopping nails, the same applies. Nails are made out of very soft steel and thus they can not impact a knife directly, all they can do is twist the edge if the chop is not powerful enough, well controlled and the backing medium rigid. Thus pretty much all you are testing is the skill of the user to chop. Cashen has noted this directly and for years with all such "tests" of knife performance, especially critial of many of the popular cutting competitions, they evaluate the user far more than they do, if at all, the actual knife.

In short, chopping through a 3.5" common nail would be a decent showcase of the nail chopping ability of the user with the profile as described in the above (10/12 with a 15 degree micro). But there is no way to infer durability of the steel without quantifing the user skill. Now there are some ways to eliminate that variable and thus reach some conclusions on the steel, but of course you would also want to eliminate user bias as well with blind steel testing, and of course never have anyone selling the product be the one who evaluates it.

-Cliff

 

[hollowdweller]

No I have not, the Bruks is much harder and thus should resist deformation more, however grinding back the edge on the Bruks to even remove 0.010" of damage is not a trivial task. If it ever does get damaged when I lend it out to a friend I'll repeat some of the above work as I will have to regrind it then anyway.
-Cliff

Cliff,

I wasn't talking about the nail chopping thing just how many chops before it loses it's shaving edge.

 

[the possum]

I would be curious if something like L6 at 66 HRC would have enough impact toughness not to chip. That would be the only way to really reduce the deformation significantly.

I'd be curious to see what S5 could do around 62 Rc. The only impact testing charts I've seen on both of these steels show S5 to be quite a bit tougher at this hardness than L6 is when tempered all the way down to the low 50's Rc.

Somehow, I saw the comments about nail cutting coming from a mile away. Which is actually a bit disappointing... As far as I can tell, we all seem to agree that controlled nail cutting does not translate to real world use, so maybe it would be best to avoid that portion of this topic all together...

 

[WILLIAM.M]

You raise a very good point.

Are there any makers willing to send you one of their Axes/Hatchets to compare??

 

[Cliff Stamp]

... just how many chops before it loses it's shaving edge.

That would be a good reference, I was thinking of the Tramontina Bolo as it should be much faster as it is much softer. I'll try both and see how they fare. I should clarify though that even though I noted both of these to high precision, 764 and 850 chops, the actual accuracy is no where near that. Quite frankly I think I would be hard pressed to move beyond say 750-850, the range is really large as there are only really small changes noted in shaving ability beyond the first 150 chops.

I'd be curious to see what S5 could do around 62 Rc. The only impact testing charts I've seen on both of these steels show S5 to be quite a bit tougher at this hardness than L6 is when tempered all the way down to the low 50's Rc.

Yes, the shock steels are so designed, I just want to see how the L6 blade will fail at that hardness, fracture seems expected obviously, but the low carbon steels will form lathe martensite which is far tougher than plate anyway (the shock steels are lathe as well), plus there is no high carbide fraction to drastically reduce toughness. But yeah, all of those steels are exceptional choices as well, high hardness and outstanding toughness so like you said, resist deformation and fracture well.

As far as I can tell, we all seem to agree that controlled nail cutting does not translate to real world use...

In general static does never equal dynamic.

Are there any makers willing to send you one of their Axes/Hatchets to compare??

It would be interesting to see how they even compare to a well ground Estwing. I may pick up one for the test group later on.

-Cliff

 

[Esav Benyamin]

This looks like testing to me ... m o v i n g.

 

[Andros]

Most knives ain't 10 inch.

True. However, knives regularly used for wood chopping have a blade of at least 8".

Would be interesting to see how well a 300 dollar custom hatchet does. Somehow I expect it won't do ten times better than this 30 $ Fiskars.

Is a FERRARI ten times as fast as a TOYOTA PRIUS? I don't think so, yet it costs about 15 times as much !

 

[Elen]

Is a FERRARI ten times as fast as a TOYOTA PRIUS? I don't think so, yet it costs about 15 times as much !

Hey, it can be, depending on where you're driving those things. The top speed may not be ten times better, but race track performance is way more than just ten times better.

 

[Cliff Stamp]

In general it is probably unreasonable to expect a linear gain in performance because the cost increases dramatically as you keep refining the performance. My point was more along the lines that the performance being promoted as acceptable/superior is usually below the capability of even low end blades.

-Cliff