Chopping Comparison: BM, SH, PH, SJ

E

Evolute

Joined
Mar 19, 2001
Messages
4,769
I found numerous planks of wood while clearing out my grandparent's garage. I decided to conduct a series of tests to compare the chopping abilities of my Busse blades. I plan on testing the Battle Mistress-E, the Steel Heart-E, the Paul's Hatchet, and possibly my Satin Jack variant.

My first test was on a board of light-medium density, unidentified pine. The board was 3/4"x4"x39". It had about six growth rings per linear inch, and weighed about .43 ounce per cubic inch. The knives were scrape-shaving-sharp, to reflect the typical outdoors-use conditions of lackadaisical maintainence.

The procedure was simple: Chop once with my BM-E, move over a foot and chop once with my SH-E, move over a foot and chop once with my PH. Then repeat. Photograph after every cycle of ten chops per blade. Count the total total number of chops per blade required to chop through the board.

As you may have already guessed from my description of the plank used for the first test, things didn't go as planned. After a few chops, the test ended suddenly when my Battle Mistress cracked the plank into pieces. Ah, well... I have more boards--heavier ones, and will be conducting more tests during free moments over the next week or so.

I did learn a few things from the test, already, though.

1) Chops made by the BM and by the SH veer slightly to the left as they penetrate wood, while chops with the PH go perfectly straight. Presumably, this is because the BM and SH have assymetrical edges, while the PH has a symmetrical edge. I will have to experiment with what happens when I chop with my other hand.

2) A result which I wasn't even looking for quickly became apparent. Because I was moving over a foot or two after each chop, I did not garner the advantage of mechanical repetition, which can make consecutive chops very accurate. Instead, I had to aim completely anew with each chop. This made it clear to me for the first time that aiming ease was proportionate to blade length. (I'm sure that there's a point at which this reaches an optimum, after which it reverses, again. However, I don't know how long my optimal length for aiming accuracy is.) The Battle Mistress was easiest to aim precisely where I wanted to chop; the Steel Heart was next easiest; and the Paul's Hatchet was considerably harder. Besides the greater chopping power of the BM over the SH over the PH, the increased aiming accurancy of my strokes greatly increased the Battle Mistress's effectiveness per chop over the Steel Heart's over the Paul's Hatchet's. (I should note that I've chopped through fallen trees with my Paul's Hatchet, and it is still a very capable chopper in it's own right.)

3) The Battle Mistress seemed to bind most in this board. It can really cut deeply through pine of this thickness and density. Nevertheless, the binding was still negligible. The Steel Heart and Paul's Hatchet did not bind at all.

More tests are forthcoming. Meanwhile, I am open to suggestions for conducting my tests as best possible. (Cliff?)

--Mike
 
Great idea Mike:cool:

I'm looking forward to more testing results.

I wonder if using round peices (assorted, dry 2-5" +/- diameter logs) would give different results and possibly show larger margins of performance between any of the chosen blades?:confused:
 
As my ol' Grandpappy used to say...
"Boy, are you hittin' where you look, or are you lookin' where you hit?"
;)
 
I pieced the cracked plank of wood back together over some graph paper, and traced the notches made by each knife onto the graph paper. I counted the squares, to figure out the approximate square area of the silhouette of wood removed by each knife before the board cracked.

Here are the results:

Paul's Hatchet: 1.5 square inches

Steel Heart: 2.5 square inches

Battle Mistress: 3.75 square inches

So, approximately speaking, Paul's Hatchet chopped 60% as efficiently in this test as the Steel Heart, and the Battle Mistress chopped 150% as efficiently. An alternate way of stating this is that the Steel Heart chopped 167% as efficiently as Paul's Hatchet, and the Battle Mistress chopped 250% as efficiently. Another alternate way of stating this is that Paul's Hatchet chopped 40% as efficiently as the Battle Mistress, and the Steel Heart chopped 67% as efficiently.

As I stated before, my test methodology inadvertantly made aiming-ease a significant variable. Therefore, these results reflect a combination of wood cutting efficiency of the blades and aiming-ease of the blades with my (mediocre) level of aiming skill. If my skills had been good enough to aim my chops consistently with all three blades, then the results of the Paul's Hatchet and Steel Heart would (presumably) have been nearer to the results of the Battle Mistress.

Further, results may differ with different hardnesses, thicknesses, and shapes of wood. My further tests will explore these differences.

----------------------------------------------------------------------

I can significantly lessen the relevance of aiming as a factor in my chopping tests if I chop repeatedly with the same blade into the same notch, instead of switching blades and notches after each chop. I may do this in my further tests.

I chose to switch blades and notches after each chop to remove arm-exhaustion as a possible variable. However, I can also remove the arm-exhaustion variable by simply taking the necessary time to let my arm recover before moving on to the next knife.

----------------------------------------------------------------------

I may try to chop cylindrical pieces of wood, as per Strabs suggestion. This would probably produce results somewhat more in line with real-world use. That may have to wait until I finish what I am doing now in the big ugly city, and get myself back into the woods for a while--probably a few weeks.

--Mike
 
Another factor that would be interesting to explore, though much more difficult to quantify is how much chopping ability you get in exchange for what sacrafice in connection with general knife chores. IOW, a machete may limb and hack like crazy but may not be so good at food prep. Likewise, a skinning and caping knife would not be my first choice as a survival knife with shelter building as a priority consideration. It is for these reasons that so many different knives are popular. It's also a reason that the NO is with me so often afield even though I probably like the SH better.
 
Mike, first off it is nice to see some comparisons of that nature being performed, you, Andrew and the others are doing Busse a great service.

As for the cracking, a decent 10" blade will tend to crack most processed lumber apart, even a 2x4" will break long before it is cut through, a 2x2" will break pretty much after the first hit. To prevent this I do most of my heavy scrap cutting on a picnic table on a piece of 2x6" . You can actually guage the penetration aspect of the chopping performance quite accurately by looking at the depth of single chops. You will want to do this a few times and get the average to reduce varitaions from wood density, swing etc. . This is of course the ideal performance, as you noted handling ability can influence the actual performance by way of accuracy and precision, so you might want to talk about both by comparing the penetration on single chops to the ratio of number of chops to cut through a piece of wood. I do complete runs with a blade and then rest and switch to another. I use the couple of minutes in between to examine the cut in detail and make some notes about the chopping, how the blade handles, grip security, ergonomics etc. .

In regards to binding, this is indeed a critical performance aspect, raw penetration ability is great, however if the blade sticks badly in the wood, then you will waste more time and energy getting it out than chopping. A simple cheap machete can easily achive greater penetration than the Battle Mistress, however a little wood work with both and you will drop the machete fairly quickly. You can quantify this by looking at the time of the chops, and how much fatigue is being induced. You can examine the fatigue by looking at the performance of a second chop with the same blade without rest and seeing how much performance was lost. You will find that blades that stick more readily lose performance more readily than blades that are more fluid in the wood. They are also less accurate because the more fluid your swing, the more accurate you will be.

In regards to the greater binding of the Battle Mistress, this may simply be because of its inherently greater penetration. You can look at this by chopping lighter so it gets the same penetration as the SH. As for the hatchet, axes come into their own on larger wood. If you look at the performance on wood that is multiple the width of the face of the hatchet you will find that its ability climbs very quickly over the other blades. An axe gets the same penetration on a piece of 8" pine as it does on a 4" piece and this allows it to knock chips out far more readily than a 10" blade which suffers a penetration loss of 50% (scales in a linear manner with the wood width).

Once you get this done, there is lots more you can look at. The very first thing I would suggest is some very fresh soft wood. Lumber is very hard as it is baked and thus it behaves differently than most fresh woods, unless the wood in your region is very hard. You won't notice a drastic difference in penetration, though there may be some differences, however binding will be influenced significantly. Working around some knots will also be useful, as a blade will pinch very heavily in wood close to a knot, so it is a worse case senario. Small diameter hardwood limbing is about the worst thing you can do with a blade, not a problem for what Busse makes, but many others have shattered or bent on the same tasks, so it is a very high end durability test.

Interesting reading, I look forward to your future posts.

-Cliff
 
On Cliff's suggestion, I have begun to test the depth of single chops. On Strabs's suggestion, I have started to include cylindrical pieces of wood in my tests.

In this test, I chopped into the rounded side of a 5-foot long by 2.5 inch wide scrap piece of molding. The wood was of unknown type, with a fairly low growth-ring density, but, nevertheless, a very dense, heavy, hard piece of wood. I chopped 12 times each with the Battle Mistress, the Steel Heart, and the Paul's Hatchet. In order to measure the depth of the notches, I slid paper into the notches, and marked the paper at the border of where it stuck out of the notches. Then I measured the distance of those marks from the edge of the paper with a clear plastic ruler with 1/32 inch increments.

The average depth that each blade chopped was as follows:

Battle Mistress: 8.7/32ths of an inch

Steel Heart: 7.8/32ths of an inch

Paul's Hatchet: 6.56/32ths of an inch

In this test, the Steel Heart chopped 119% deeper than the Paul's Hatchet, and the Battle Mistress chopped 133% deeper than Paul's Hatchet. An alternative way to state this is that Paul's Hatchet chopped 84% as deeply as the Steel Heart, and the Battle Mistress chopped 112% as deeply as the Steel Heart. Another alternative way to state this is that the Paul's Hatchet chopped 75% as deeply as the Battle Mistress, and the Steel Heart chopped 90% as deeply as the Battle Mistress.

However, this test also had complications which skewed the results: The Battle Mistress tended to shatter the immediately surrounding wood, sending wood chips flying. This meant that I ended up with fewer chops on which to base the average. Further, the deeper chops were more likely to send chips flying, thereby forcing me to collect data from the shallower chops, skewing the results of the Battle Mistress lower than they should be.

---------------------------------------------------

The deepest chop recorded from each blade was as follows:

Battle Mistress: 13/32ths of an inch

Steel Heart 10/32ths of an inch

Paul's Hatchet: 8.5/32ths of an inch

The Steel Heart chopped 118% deeper than the Paul's Hatchet, and the Battle Mistress chopped 152% deeper than Paul's Hatchet. An alternative way to state this is that the Paul's Hatchet chopped 85% as deeply as the Steel Heart, and the Battle Mistress chopped 130% as deeply. Another alternative way to state this is that the Paul's Hatchet chopped 65% of the depth of the Battle Mistress, and the Steel Heart chopped 77% as deeply as the Battle Mistress.

The performance of the Steel Heart relative to the Paul's Hatchet in average depth was fairly consistent with the maximum depth performance of the Steel Heart relative to the Paul's Hatchet. While the results for the Battle Mistress are skewed too low, even the artificially low results are 12% better than the Steel Heart in the average depth, and 130% better in the maximum depth.

I'll run the same tests on the flat side of the same molding within a few days.

---------------------------------------------------

I welcome your feedback.

--Mike
 
I do most of my heavy scrap cutting on a picnic table
Click to expand...

thanks cliff, i just ruined my new redwood table and mrs skunk has left me. i think she has a computer "friend" on here she's flirting with. hope he has a lot of infi on hand... she doesn't come cheap!
 
Mike, wood shattering is a big problem with larger blades, fresh wood if available, solves this problem, otherwise fresh lumber, or the harder grades works decently. Informative results in any case. What you might want to look at next is how this penetration translates to estimating direct chopping performance.

If you follow your lines correctly, and both blades can break out the wood, then both performance ratios will be equal. But on larger wood this will not be the case. You will find then that the larger blades will pull ahead strongly as they have a much greater ability to clear out the wood. Twisting the blades after the chop to break out chips will increase this difference.

Skunk, get an INFI table one and use a particle board top, problem solved.

-Cliff
 
Very interesting testing, Evolute. I have wanted to see some comparative testing between those models for quite some time; thanks for taking the time to do some testing :)

One thing I have noticed when comparing chopping-class blades is that different hardnesses of wood will change how the blades chop relative to eachother quite a bit. An extreme example of this is comparing, say, a Steel Heart to a machete. The machete beats the SH hands-down in softer woods, brush, etc., but is either beat out by the SH in very hard woods (say seasoned oak or hickory) or at the least has a significantly smaller advantage over it (depending on the machete). I would be interested to hear your thoughts on how the blades compare in the following (ideas):

  • brush in general
  • small diameter soft woods (+/- 2")
  • small diameter hard woods (+/- 2")
  • larger diameter soft woods (+/- 5-6")
  • larger diameter hard woods (+/- 5-6")
  • extremely hard wood in varying sizes, small to large (seasoned oak, hickory, etc.)

Binding has also been a fairly large factor in my experience. I have a machete that I'm using at the moment, for example, that penetrates wonderfully but binds readily also, and has to be yanked out of the wood after almost every chop. This hampers its effectiveness quite a bit. One area where I noticed the binding does lessen is in very hard woods, where its penetration is not nearly as much. However, as it penetrates less, its chopping performance obviously goes down, and I haven't yet found the best of both worlds (although convex primary grinds seem to help). Also, its integrity is not great, and it flexes quite easily using just a finger, so prying chips out (as Cliff mentioned) is not a good idea. When chopping this very hard wood, it does make ringing noises that bother me in that it seems ready to shatter at any moment. I don't know if my fears are totally founded, but I avoid chopping very hard wood with this machete.

I look forward to seeing the results of your further testing and, again, thanks for taking the time, it's much appreciated :D
 
Wood class is a good point. A blade like the Battle Mistress, is much thinner behind the edge than a typical machete, and thus the machete is at a disadvantage on hard woods where the penetration is low. However because the Battle Mistress hits 1/8"+ fairly quickly, on deep cuts the machete starts to pull ahead.

My perspective on this is that on really soft wood you don't much care as you are chewing through it anyway. However it is the hard wood that makes you work for it. For completness you would want to look at a very hard wood (<1/2" penetration) to a very soft wood (>2" penetration). And thus you could bound the performance of the blades between both extremes.

Lots of great points raised by Andrew which proves just how nontrivial "chopping" really is when looked at in detail.

-Cliff
 
For this test, I used 2x4s of Douglas Fir with the tightest growth-ring density readily available, about 8 rings per inch. This wood turned out to be far harder than I had expected, and not particularly prone to shattering, thus being well suited to this test. I simply chopped straight through 2x4s with the Paul's Hatchet, the Steel Heart, and the Battle Mistress, counting the number of chops necessary to completely cleave the boards in two.

My results were as follows:

Paul's Hatchet: 288 chops

Steel Heart: 215 chops

Battle Mistress: 140 chops

In this test, the Steel Heart chopped 134% more efficiently than the Paul's Hatchet, and the Battle Mistress chopped 206% more efficiently than Paul's Hatchet. An alternative way to state this is that Paul's Hatchet chopped 63% as efficiently as the Steel Heart, and the Battle Mistress chopped 154% as efficiently as the Steel Heart. Another alternative way to state this is that the Paul's Hatchet chopped 49% as efficiently as the Battle Mistress, and the Steel Heart chopped 65% as efficiently as the Battle Mistress.

Then I had a friend of mine--a far stronger, better coordinated, more
skilled chopper than myself--repeat the test. His results were as follows:

Paul's Hatchet: 160 chops

Steel Heart: 101 chops

Battle Mistress: 65 chops

In this test, the Steel Heart chopped 158% more efficiently than the Paul's Hatchet, and the Battle Mistress chopped 246% more efficiently than Paul's Hatchet. An alternative way to state this is that Paul's Hatchet chopped 63% as efficiently as the Steel Heart, and the Battle Mistress chopped 155% as efficiently as the Steel Heart. Another alternative way to state this is that the Paul's Hatchet chopped 41% as efficiently as the Battle Mistress, and the Steel Heart chopped 64% as efficiently as the Battle Mistress.

If you combine our results, they are as follows:

Paul's Hatchet: 448 chops

Steel Heart: 316 chops

Battle Mistress: 205 chops

Combined, the Steel Heart chopped 142% more efficiently than the Paul's Hatchet, and the Battle Mistress chopped 219% more efficiently than Paul's Hatchet. An alternative way to state this is that Paul's Hatchet chopped 71% as efficiently as the Steel Heart, and the Battle Mistress chopped 154% as efficiently as the Steel Heart. Another alternative way to state this is that the Paul's Hatchet chopped 45% as efficiently as the Battle Mistress, and the Steel Heart chopped 65% as efficiently as the Battle Mistress.

Stay tuned for the results on 6" hardwood logs.
 
Informative results. As expected, when the chopping ability increased, the blades pulled further apart. Something you might want to think about is repeating the cutting at least once. This would allow you to bound your results with a simple range. This would allow an estimate of the kind of variation in the work. It also allows you to track your skill with the knife.

In regards to the numbers, when they are given in text, most will find it hard to read. You can usually read them easier if they are isloated in a table like :

448 100 071 046
316 142 100 065
205 219 154 100

You would of course want headings and all that. Tables are not easy to do direct in text here because of alignment issues, the above should be right aligned (decimal aligned is best) for optimal readability, this is why I put the zeros in for padding. It is easiest if you can generate them elsewhere elsewhere and paste in a gif. Direct html works, but if you foul it up you can bring down a thread.

Keep on chopping.

-Cliff
 
Strong work, Evolute. Thanks. Based on my own experience with my PH I pretty much limit it to limbs/brush under 1.5", and use a more efective tool for larger stuff. My dull Gerber back-paxe outperformes my razor sharp PH because of its mass/gometry, confirming (to me) the limited scope of my 9" PH. So I think to myself, "self, what would an 11"-12" PH2 variant be capable of?" Is this something worth lobbying for??? Hmmm, how about 11.5" O/A, tapered tang, and Fusion scales? But then it'd be competing with the Wildlife Hatchet, and the price difference just wouldn't be feasible... I'll shut up now.
 
BURPPPP! Was just reading through some old test threads and thought some others might enjoy this. Sorry Matteo :o
 
Off the subject a bit, a gransfors small forest axe might be a better match for the FBM and FSH.
 
Umm, Im new here, and I dont know much about things edge related in nature. I do know that my gransfor mini outchops my steel heart fusion. By how much I cant say in a scientific way. Maybe its just my experience with them. I have a FBM user and a wildlife on the way.
 
good test. The FBM is just so mass forward that it just cuts deeper. You can feel the forward mass. Good comparison:thumbup:
 
You must log in or register to reply here.
Back
Top