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Machete reviews

M

matthew rapaport

Joined
Jun 23, 1999
Messages
1,209
I'll go first. The following link will take you to my personal head to head review of the Livesay RCM and the Aki SBM machetes. Let me know what you think.

<a href="http://www.crl.com/~mjr/sbm_rcm.html">Click here for SBM/RCM review</a>
 
If you like thin machetes also look at 'corn knives' as they're called at a local hardware store. Austrian, 18in blade, 0.075 inch thick, about 2.5 inches wide and decently tempered. I use one for berry vines, which it handles well, and broke a piece off of the tip at the end of a job clearing a lot of established ivy. It would have been worth it for the just the ivy job, my ax still has a fair number of nicks in it from the stuff that the knife had a hard time with, and I managed to cleanly saw the end off and end up with a 12 inch knife, which is handier anyway. I toasted a bi-metal hack saw blade sawing the tip off. A good edged tool for stuff around the house, at a bit over $10.
 
Matthew, great review! For another perspective and some more pics, take a look at my review, too (you can see it at Ross' site or the original on my site): http://www.geocities.com/CollegePark/Lab/1298/aki.html
I have been using the SBM for some pretty heavy stuff and it has held up well. I did finally put a couple dings in the edge in the last few times I've used it on tree branches and other wood. The 1/16" is designed for thin or thick, but non-woody, stuff. It works for other applications, but again, use a knife for what it is designed for! The 1/16" is a lot more hardcore than most would think, though. Ross makes his knives based on what you tell his they will be used for. If you want an SBM with 1/8" or thicker stock, he'll do it, so don't think he is a one-trick-pony, whatever you do!

------------------
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Madpoet (Mel Sorg, Jr.) Tribute page:
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I would not have guessed that the RCM would come near to the cutting ability of one of the Ontario's let alone actually do better than it (on soft to moderate materials, I would have expected iton hard woods). Very interesting reading.

-Cliff
 
Which brings up an interesting question ... Matthew, out of the Ontario and RCM, which one reaches 1/8" thickness faster? The bevel on the Ontario is short, say 1/4", so the blade is a full 1/8" when it's 1/4" from the edge. How fast does the RCM reach 1/8"?

Joe
 
Hello all, thanks for the comments. A few of my own...

Chiro, it was your review that prompted me to order Ross's machete in the first place, nice job!

Cliff and Joe... I'll let you guys do the geometry, but if the spine is 3/16 and it is a true flat grind all the way to the edge at 1 13/16" (an assumption violated only in the last 1/16th") you can work out the trig of it with a tangent. But just as a guess I would say somewhere between 1" and say 1.25 inches it probably sees about 1/8" thickness.

I would say that this explains why the RCM cuts better than my Ontario. There is also the matter of a better balance and more comfortable handle. But I emphasize my Ontario because I have the beaver tail model, and I don't believe that is the best one to compare with the RCM. The beaver tail model doesn't look anything like the RCM, but Ontario does have a straight-back version that looks more or less like it in outline. Perhaps one of you can tell me if this particular Ontario version also thickens rapidly from the edge and then has the full 1/8 thickness through most of the blade width?

Thanks again. Glad you liked the review. I'll continue to add things as they occur to me and/or I do more testing. For example, I added a sentence about the importance of a lanyard hole, which my SBM does not have, and Ross wrote me to say that he has always done a hole at no cost for any customer who asks for it. He says he doesn't get much call for it, and pointed out that I didn't ask, and he was right, but in the mean time I also added that fact to the review.
 
Matthew, thanks for the details. I did some comparisons with the Ontarios I have and the RCM would get thinner faster because of the flat grind. However that is not what I was thinking about, one of the factors yes, but primarily, I would have expected the Ontario's to cut better because I had assumed the bevel on the RCM would be a lot more obtuse. This is part because of the somewhat "combat" nature of Newt's work and Jeff Randalls comments that he had to do an hours work on the edge of his to get it acute enough for him.

-Cliff
 
Matthew -- I'll check when I get home, but I believe the grinds on my beavertail and 18" Ontario machetes are identical. Thanks for the info

Joe
 
After my Ontario's fractured on the hard woods awhile ago I spent some time trying to figure out why comparing them in detail to some other machetes at a variety of work. The conclusion I came to is that they failed because they didn't have the necessary cross section to support their chopping power on hard woods.

Now with this in mind the RCM starts to look at bit fragile as it has an even smaller cross section (edge wise) and yet more weight (thicker spine) so the power will be greater. That is a dangerous combination. The materials are similar and the final RC is as well. The saving factor however maybe the heat treat. Newt could be tempering differently so that the edge could stand the strain.

Anyway, the point of all that is that I am now wondering about the suitability of the RCM on hard woods, specifically small diameter ones (1/2" inch). Is it intended for such use? Has anyone used it in such a manner?

The only comments I have seen in this regard are some posts on Jeff Randall's forum about RCM's chipping when hitting hard objects and being sent back for sharpening - not a positive sign, but how much so depends on the size and nature of the damage.

-Cliff
 
On the Ontario failures .... as I recall pieces of the blade broke off, which is what happened to the 18in blade corn knife that I was using. I was clearing some established ivy, chopping against the hard clay ground and hitting not only tough roots but rocks and such. The failure mode was interesting as it looked like the spine wasn't thick enough to support the impact loads, and the top part of the blade buckled a bit on the end of the blade and eventually chipped out.
 
The failures were basically semicircular pieces that broke away while I was limbing out some dead trees. On the 18" machete the pices were very large, the size of my thumb. On the 12" blade, the fractures were much smaller, say 1/2 cm in diameter.

-Cliff
 
The pieces that broke out of mine were maybe two to three inches across, so it's interesting that the size of the pieces seems to correlate with blade stiffness. Mine broke out after a fair amount bit of abuse on a specific job so I wouldn't consider it a failure to a defective product, rather it was stressed beyond it's endurance limit for an extended period. Whacking a blade a few times against something hard doesn't mean that it'll stand up to such use, as some others have also observed that their knives just broke one day after chopping with it, sometimes for years.
 
Johno, metals have crack fatigue lives just like they have other fatigue lives (bending and such). For decent steels they are usually very high. However a brief period of extreme high intensity use can start a crack and thus greatly speed up the process - the full effects only seen months later. For someone to suddenly see a gross failure in a strong blade I would guess that it had seen really heavy use sometime in the past.

-Cliff
 
Cliff, I don't know what to say about what you read into that review. I think the RCM is probably a good deal stronger than the Ontarios first because of the thicker spine, next because the metal, while ordinary carbon steel is probably treated better. As for using it on hardwoods, I've already told you that I used it to split pine logs up to 6" in diameter though this was very hard work, it certainly had no problem at 4".

I don't think Newt designes his machete's for "combat" per se. His edge configuration is optimized for certain types of plant tissue, notably large marijuana stalks! These are much harder and more fiberous than jungle vines, but not as hard as pine or oak. I'm a big fan of matching the tool to the job. If you are going to be cutting light brush and really soft vines, get a different machete (like the Aki SBM). If you are going to cut hard wood all the time, get an axe, hatchet, woodsman's pal or bill hook, that's what they are made for. The RCM seems to work best in that in-between realm where the tissue is a little too large or hard for the SBM, but not for felling hardwood trees.

That being said, you mentioned stalks 1/2" in diameter of woody tissues. I tried the RCM on plant tissue like that as much as I could and from what I could tell, it goes right through them, one cut, just about every time.
 
Matthew, concerning the RCM I would agree that in terms of gross blade strength it would be greater than the Ontario because of the thicker spine. What I was wondering about it the durability/strength of the actual edge itself. In that aspect the RCM actually has a thinner cross section than the Ontario. While this is quite probably why it cuts better it also would make it weaker. However as you said there is a difference in the heat treat. As for cutting hardwood, I have machetes that can do that with no problems. I was just curious if the RCM could.

However to mix things up, Jeff Randall has commented in the general forum :

http://www.bladeforums.com/ubb/Forum32/HTML/000277.html

That when he compared the RCM to the Ontario's the RCM fared worse on light vegetation, because the RCM had a thicker edge. This is the exact opposite geometry that you describe. Is it possible that Newt slimmed down the profile on the RCM's?


-Cliff
 
Thank you for pointing me to that review Cliff... Very interesting, but I don't understand how what Jeff could describes is possible (assuming we are not talking about different machetes)...

As you observed at some point, the cross section of the Ontario becomes 1/8 inch about 1/2" or less from the edge. With the RCM, it doesn't go to 1/8" until a good inch up the blade. How could the Ontario *possibly* have a thinner edge profile? As for the immediate edge, one can always thin that out. I thinned mine by about 5 degrees, though I did it AFTER these tests, but It cuts the light stuff much better a little thinned down. You have to do this with the Ontario to get the best edge as well, and I think the RCM steel will stand up better than the Ontario, but I can't prove it.

I do want to clarify something though... Neither the Ontario nor the RCM would cut free standing grass (mind you this stuff is 4' and more high) worth a damn. What I did was to grab a hank of grass in my left hand and then slice through the bundle of strands about 1' from the ground usually at about a 45 deg. angle. Here the RCM did better than the Ontario, but not so much better that it would be worth almost 10 times the price on that alone. I think it did better because it is better balanced and the stroke is more comfortable, the handle more condusive to keeping the edge in the same plain as the stroke, etc.

I have to agree with Jeff that if you're going to cut light stuff, you're better off with a thin machete. Newt is trying to make a cutting tool that cushens the hand from numbing effect of using a too-light tool on harder tissues.
 
Matthew, concerning Jeff's remarks, the only thing I can figure is that the soft vegetation he is cutting is much thicker. This would make forcing the overall thicker RCM through it harder than the Ontario. It would be easy to evaluate this, take a carrot or similar and see if its easier to cut it in half (standing) with the Ontario or the RCM. Fatigue is the other factor. What are the masses of the RCM / Ontario / Aki? I would bet the Aki generates almost no hand/wrist strain at all.

-Cliff
 
The Aki is very light. That, along with its thinness, and its convex edge, is what makes it such a great cutter. But its strength (so to speak) is also its weakness when applied to harder materials. It bounces back from them and delivers something of a shock to the hand, like hitting a hardball with a softball bat. The RCM is designed to keep the shock from the hand and arm, that is the whole point to its weight, handle configuration, etc.

One would expect the handle of the RCM to be more comfortable than that of the Ontario. If it isn't, why would anyone pay so much more for it? As for weight, I think my Ontario beavertail model was just a hair heavier than the RCM though it is a bit shorter because of the very wide blade that is a full 1/8 inch wide through most of its width.
 
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