Martindale has a reputation for high quality machetes, which I heard about on line, through generally favorable recommendations. This particular blade looked interesting, and I was curious about the basic shape. A sample was provided by Daren Cutsforth of Cutsforth Knives .
This is a machete class blade, weighing 510 g, with eleven inches of cutting edge. It has a strong distal taper, from just under 3/16" near the handle to about 1/16" near the tip. This design gives you the advantage of a very thin tip for high performance cutting in soft materials, as well as a more durable edge near the handle for heavy chopping. The balance is quite blade heavy, the center of mass is 4.7 cm in front of the handle, due to the hump at the tip. The handle is long, 11.5 cm of grip surface, which is allows a close up grip for light work and a far back grip to increase power for heavy cutting. The grip is well shaped, comfortable in hand, with a large swell-knob for security as well as something to drive off of.
Just how much distal taper are we talking about and how acute does the tip get? Well the edge grind is uniform in width, just under a quarter of an inch, combining this with the distal taper means that the edge angle changes smoothly as you run out towards the tip. Near the base of the blade the edge is 0.145" thick and thus the angle is about 19 degrees per side. Towards the middle the edge thickness has dropped off to 0.100" and the angle down to a decently acute 14 degrees per side. Out towards the tip the edge thickness has fallen to 0.055" thick and the angle to a acute seven degrees per side. The only blades I have with edges this acute are those like Opinels, and thus you can see the very high cutting ability it offers.
The fit and finish is easily the best I have seen on a machete. Many machetes have wavy edge bevels, some with secondary edges of very obtuse grinds. However the edge on this knife is well formed. It is a nice and even grind from start to finish. I would not call it sharp, but the profile shape is functional, which is of critical performance. A full sharpening at most just calls for a burr removal and stropping, or a simple filing if you prefer that edge condition. The handle is clean, no cracks anywhere and no gaps, except on the outside of the swell knob, which isn't significant as you don't hold onto it there anyway.
However, the handle is coated and is a bit tacky. A few minutes of sanding, and then a light coat of boiled linseed oil fixed this problem. The edge also had a few small impaction points, which is common for larger blades of this type, but was usable NIB. I fully sharpened it to check the edge grind flatness and to determine the quality of the edge it would take. I first used a file to just test the bevels for flatness, they passed being even the whole length. I then cut the burr off with a 600 and then 1200 grit DMT hone. I then stropped on CrO loaded leather and the blade was shaving sharp, able to cut through 1/4" poly under a 1000 g load in only 0.25 to 0.5 cm, which is a very high level of sharpness indeed.
This is a shot from the Cutsforth Knives website .
The first part of the review will be with the knife as it is NIB, no significant changes to the blade design.
So we have a fine tip for light cutting and a heavy base for thicker chopping, sounds nice, does it actually work? Yes, very well. I used the Jungle knife first in the kitchen and the blade was very versatile. The very high performance tip sailed through vegetables and meats, as easy as than the normal Henckels knives I used, which I have even reprofiled. The more obtuse edge near the base could easily handle sloppy joint separation on poultry. Also, the wide tip gives you a lot of room to move vegetables around. The knife is also not so blade heavy, that it is awkward for lighter cutting with a forward grip. It is workable for point cutting like skinning chicken and even peeling potatoes. In general, on cutting cardboard, rope, and various fabrics, the thin and acute tip showed a significantly higher cutting ability than most other large knives I had. Even the thicker edge near the handle cut very well, it took 11.6 +/- 0.7 cuts to point a hardwood dowel.
What about the raw chopping ability? I first looked at this on some scrap lumber, as it is clean, and I can make sure that there are no knots, so it is very easy on a knife. The Jungle knife had solid penetration and overall was just slightly behind the Tramontina Bolo in regards to penetration. The Jungle Knife is a little thicker and thus moves slightly more fluid in the wood, but not enough to overcome the penetration disadvantage. The only real problem was that the balance point on the Jungle Knife is actually above the handle due to the hump which made it a bit awkward for me at first, but this will go away in time as you adapt to how it feels. The optimal blade profile for this type of chopping in seen in something like the Battle Mistress from Busse combat which will match the penetration of these blades, but is much more fluid in the wood. Of course, a small quality axe like the Wildlife Hatchet from Gransfors Bruks, will bind even less, so it is the tool of choice, but of course has drawbacks for a lot of lighter cutting, and the hatchet only really offers a significant advantage on much larger wood where the blades fail to clear it out from the cut.
How about misc uses? Well the hump can actually be used for very rough cutting. For example it had no problems hacking up a few sods. The cutting ability is enhanced by the distal taper and the hump concentrates the force resulting in a very high pressure. The handle comfort is high even in this reversed grip. The same technique also allows you to beat dead and dried limbs off of trees as they can be very hard on a knife edge. Due to the thin spine, and the sharp corners, the hump could beat them off just as easily as I could cut them off with other large blades, this type of wood tends to crack rather than be cut, however even on fresher small limbs, the spine could easily knock them off. The large surface area of the hump also allows it to work as a makeshift scoop (I was moving some snow and ice) and paddle, much more so than regular machete style blades.
I started by time looking for very light vegetation to try out the cutting ability of the tip. It was not trivial to find this as we still had a lot of snow, but I was able to turn up enough to get a decent comparison of this blade and a few others including a custom Livesay RTAK and a Tramontina Bolo. The Jungle Knife far outperformed these blades on such vegetation. The difference is even larger as compared to a traditional bowie design like the Busse Combat Battle Mistress, which while cutting well, doesn't have the reach, and is vastly over built for such work. We are not talking about a small difference of a few percent here, but easily more than two to one, as the edge on the Jungle Knife is just so much more acute. In fact the first few times I used it I thought I had missed because the resistance was that low. This higher cutting ability drastically lowers fatigue on light vegetation. I also spent some time using the tip as a draw knife and it was able to clear out wood much faster than the other two knives I had on hand, though the rounded spine on the RTAK was by far the most comfortable to use.
Bucking up various felled woods, the Jungle Knife performed at about 69 +/- 5 % of the Gransfors Bruks Wildlife hatchet. This is lower than its actual ability by around 10% I would estimate. The problem is that I was unused to the balance so my cut placement was off. Getting specific, the balance is high on the blade, above your hand, and it feels like the blade wants to actually come back at you, instead of pulling down as normal on blade heavy knives. As well, also because of the high balance point, the knife has a tendency to roll in the handle if you are used to lower balanced knives. This isn't a critical problem, just something that you have to get used to. Everyone that I handed the knife to, tended to comment that it felt much "better" with a reverse grip with the hump pointing towards the ground. Anyway, during the bucking, the handle was solid, secure and comfortable. There was no edge damage, and the blade had cut through knots several times. In regards to binding and chip clearing ability, it was similar to the Tramontina Bolo.
Are there any drawbacks to the design for brush work? The only real problem is with cutting smaller branches. Limbing is very hard on a blade, much more so than felling as the force is concentrated in a very small area, and the limbs are a lot less stable than the tree trunk, so there is a much higher chance of lateral loads across the edge, which is the real problem. The obvious question is why not just use the thicker part of the edge near the base for this cutting? Well a lot of the time, when the branches are not very dense you can in fact do this, so it isn't an issue. Using the blade in this manner, it has solid performance. No problems were evident when the blade was used in this manner, even on the hardest branches. However much care had to be taken to avoid contacts with the tip, which means progress is relatively slow.
In general, this isn't a realistic way to work though, as when the branches get dense, it is next to impossible to avoid cutting with the tip as you have to cut them from the outside and work in. To make this as easy as possible I started out with a small piece of pine, about three inches in diameter, and the limbs were still live wood. I then proceeded up from the base of the tree, working as precise as I could, with very low force, mainly from the wrist, with just enough force to cut the branches. However by the time I had worked about half way up the trunk, several edge deformation were clearly visible. When the limbing was complete, about a half dozen places had visible deformations. On average they were less than a mm deep and a couple wide.
I then spent some time doing about the worst thing you can do with such a blade which is sweeping the dead and dried hard limbs off a trunk using heavy swings. I did about five hundred chops or so all along the blade as I wanted to see just where the damage would set in. The resulting the deformations were limited to the top one third of the knife and were fairly extensive in that region. The dents ranged from 1 to 1.5 mm in depth and up to 5 mm in length. This isn't an indication of a poor heat treat or steel, just simply a limitation of the the very acute angle. Here is a shot of the edge damage :
The blade offers a strong combination of overall cutting ability due to the distal taper and varying edge angle. The balance is blade heavy enough to allow for solid chopping performance, at about 75-80% of the GB Wildlife hatchet, while not being as fatiguing on lighter work, due in part to the large handle length which increases grip versatility. Overall the blade cuts very well NIB. Out near the tip the cutting performance is on par with a a fine paring knife (vegetables and meats). The edge sharpens easily, even with cheap hones, and can be filed and maintained with a butchers steel as well. However for woody brush work, the thin edge near the tip is a concern and care will need to be taken, or modifications made to the geometry. The Jungle Knife does not have the raw chopping ability nor reach of a traditional straight machete, which generally have eighteen inch or longer blades, but this knife is [b]much[/b] more versatile with higher performance over a wide range of tasks.
A harder steel would be advantageous as it would produce a stronger edge. This would have two immediate advantages. First off it would give greater edge retention, so less sharpening, and this is always a good thing. If the hardness was left no higher than 56-57 RC, it would still be easily able to be filed, so there would be no complaints from people who like to sharpen in that manner. Secondly, the edge durability would increase. This means that you can either use the blade for rougher tasks with less damage, or lower the edge profile for more enhanced cutting ability. I would also like to see a slightly longer blade, but then again Martindale has many larger machetes and this is more of a "knife" than a true machete. A slightly longer handle would be an asset, as you could choke back further to increase the reach and raw ability, plus when you gripped forward, for precision cutting, the balance would be closer to neutral and thus less fatiguing.
The edge geometry could also use some modifications. First off, near the base where the edge is at ~18-20 degrees per side, there is no real need for the entire edge to be at this angle, only the last mm or two at most. Above this the blade should be thinned out to increase cutting ability. In effect add another bevel above the existing one, which adds "relief" to the cutting edge. The easiest way to do this is to simply use a convex edge bevel which sweeps down strongly in the last two mm or so to create the actual edge bevel. Above the very edge, the convex bevel should sweep back strongly providing relief for the cutting edge and enhancing cutting ability.
In regards to the edge damage seen, that can be prevented by changing the edge angle. However considering that this is a "Jungle" knife, and thus intended for softer vegetation, the design makes sense as it currently stands. Leafy vegetation as well as grasses and such are easily handled by the thin and acute tip, and the very high cutting ability will be appreciated during extended work. However the Jungle Knife does make a fine blade for harder, woody vegetation with just a slight edge modification, which can be done by the user in a few minutes with a file. Basically add a small secondary bevel running back from the tip. The nature of the bevel is dependent on the skill of the user, and the hardness of the wood. Experience is the only way to find the optimal angle, but about 15 degrees per side is a decent place to start. Mine is close to ten, but we have mainly soft woods around here. If you want to be able to do some bone chopping near the base of the blade, you will want to add a secondary bevel here as well, something like 25-30 degrees per side would be a place to start.
There are also some relatively minor issues. First off the spine is rather sharp. This does have a lot of advantages for use as a rough hacker, but also makes various spine handling work uncomfortable, such as using the blade as a draw knife. In general, it will be regarded s a low grade of finish. Similar with the handle, the tacky finish it comes with, while protecting the wood, isn't what I would prefer for actual use. It binds to the hand strongly and causes skin irritation with extended use. A light coat of boiled linseed oil is a very user friendly finish. Finally, the edge sharpness was poor in regards to most cutlery, but high compared to other machetes. It could be improved by a huge amount by finishing with a buffer.
The edge of the knife was modified as noted in the above to increase the cutting ability near the base and enhance the durability near the tip. A convex was applied which roughly double the angle towards the tip, and swept back the bevel near the handle to almost twice its width. The two main aspects I was interested in was the angle necessary to give the edge near the tip the necessary durability for limbing, and how the relief increased the cutting ability near the base of the blade.
The cutting ability near the base of the blade was significantly increased by the altering of the edge profile. There was a slight change in edge angle, down to about 15-16 degrees per side, and the addition of a very strong relief of about 8-10 degrees which was close to a full inch wide. Some wood whittling showed showed the increase in cutting ability readily as well as just slicing up some foods in the kitchen. A quick check on the hardwood dowels revealed it was now taking only 9 - 11 slices to point the dowels, an increase of about 10% . Some chopping and limbing also showed a significant gain in ability as well. Near the base of the blade, it was now performing much closer to the Tramontina bolo.
During this time I started to use a grip way back around the end of the handle for maximum reach and power, mainly on the thicker woods. As the handle swells out to the side in the end hook, a grip where this was contained in my hand was uncomfortable. To solve this problem I modified the profile slightly. I used a small chip knife to rough out the profile and a rasp and sandpaper to finish the job. I basically brought it level to the side flats on the right side, I am right handed. This only took about ten minutes. I then finished with a coat of boiled linseed oil. Now the handle sits much more comfortable contained in my grip and allows extended work with such a grip with increased comfort and security. Here is a shot showing the modified handle :
The increased edge angle near the tip allowed several days of careful limbing with no problems. As the edge profile was still more acute than the Tramontina bolo in that region, the cutting ability was significantly greater. The Jungle knife felt a lot more surgical, as I could use less force and thus tighter and more controlled swings. The procedure was generally a two part method. First I would choke up on the handle and use the upper part of the blade near the tip to lightly pop off all the small limbs and basically clear out around the heavier branches. I would then grip way back on the handle with the swell knob resting underneath my thumb, and use a heavier and wider swing to cut through the larger branches, the largest ones needed to be notch-cut. With the smaller ones clear out of the way, I could cut with confidence without fear of deflections or glances which could possibly damage the edge.
However on the ingrown hard woods, this wasn't possible as the branches were too intertwined and thus it was impossible to cut them individually and thus you are forced to used a much rougher method of trying to sweep multiple limbs off at a time. This means the probability of lateral impacts (twisting) goes right up, and sure enough after doing this for awhile the blade got dented. The knife was only 0.012" thick behind the dent, and the angle of the edge in that region was ~12.5 degrees. Given past experience with blades of this hardness (45-48 RC), on this type of work, this is what I would expect to happen. Now I could just increase the edge angle again until the necessary level of durability is reached, however the cutting ability was so high on the softer vegetation I did not want to do it. To enable the Jungle Knife to cut such wood I decided to sharpen the back, which in fact has the ideal profile for limbing, a sharp concave curvature.
At first I tried just a steep bevel, just a few minutes of grinding then a quick sharpening. The bevel was about 18-20 degrees per side and started about 2cm below the top of the hump. However this didn't work well, it was basically a sharp club. I could beat off the harder branches, but there was little in the way of cutting ability. But the blade did feel good in hand while doing it, and the idea had promise so I did some more grinding. I cut the edge down to ~15 degrees per side, and put in a heavy back bevel for cutting relief. I also extended the sharpened portion of the spine right up to the top of the hump. Now it worked quite well. I could use the primary edge for fresh branches and the sharpened spine to deal with the very hard ones and the heavily ingrown wood. The edge angle is robust enough so that it holds up to even the heaviest of use. It also makes a lot of the misc. hacking like on sod, roots and bone much easier, though the edge will take visible damage on all of those. The amount of damage could be reduced with an increase in edge angle, but it works well on woods which is what I primarily use it for. Here is a shot showing the modified edge profile :
I left the top of the hump unsharpened for two basic reasons. First of off for basic safety, and sheathing concerns. Secondly, if the top was sharpened it would be impossible to use as a draw knife, and very difficult to use when splitting. Both of which are nice abilities to have for a large bush knife. Of course if these are not concerns of yours, you are better off sharpening the entire back and getting much cutting ability.
Edge retention? As it is made of a softer steel (I have seen the hardness quoted as 45-58 RC) without a high alloy content, don't expect the edge to last long if you are slicing a lot of abrasive material, but I could still easily get a day of wood cutting out of it without needing to touch it up. At the end it would still be sharp enough to handle light vegetation and it could be restored to within a few percent of optimal by just a few passes on a fine butchers steel. If you like aggressive edges then a file once a week and regular use of a butchers steel to create and maintain a micro-bevel is the way to go. If you like a more polished edge, then a fine ceramic rod will work well also, as does stropping, I prefer CrO for a loading compound. If you do have to slice a lot of abrasive material, then leave the edge as rough as possible to enhance both the cutting ability and the edge retention.
Corrosion resistance? This is a low alloy steel, so expect it to rust very quickly if exposed to salt water or fruit acids, or even left wet. Personally, I oil or grease the edges after use, and will just clean off any light rust which sets in on the flats. After awhile the flats will develop a patina which will act to increase the corrosion resistance. The oil or grease on the edges will also act as a lubrication to increase cutting ability, and decrease wedging in thicker woods.
With the edge and handle modifications, the blade now offers very strong performance over a wide range of tasks. It has proven to be a very versatile large knife, combining a very solid compromise between the raw cutting ability of a large machete, and the fine cutting ability of a small utility knife.
You can comment on this review by dropping me an email : cliffstamp[REMOVE]@cutleryscience.com or by posting in the following thread on Bladeforums :