Becker Machax from Camillus


A shot of the Machax :

side
machax

The review consists of :

Specifications

The Machax is 15" long and weighs 620g. It has a 9.5" blade with a black epoxy coating, ground from 0.25" of 0170-6 uniformly hardened to 58/59 HRC. It has a shallow sabre-flat grind of 6.5 degrees per side which tapers to a secondary edge bevel of 25 degrees per side. The handles are thick and are made from GV6H, a 60% glass filled thermoplastic polymer alloy, Zytel is a similar alloy but has 15% glass. The Machax comes with a Kydex sheath.

The edge grinds vary significantly in width over the length of the blade from about 0.05 to 0.1 inches wide and the changes are not smooth nor constant in direction nor symmetrical. The primary grinds also start with abrupt 90 plunge cuts which are strong stress risers and thus create weak points. The handle slabs are also not flush with the tang. One is too high and there is a small visible gap between the other and the tang. The blade coating is however uniform. The blade comes with a Kydex sheath which holds the blade securely and has a drainage hole.

The overall quality of construction is inferior to high end Kydex work. In particular the Kydex sheath which came with the Battle Mistress has thicker webbing and Kydex, the belt loops are more cleanly cut, the snaps are of higher grade and better center, and there is a more secure attachment of the webbing to the Kydex. The retention strap on the Machax could be completely pulled off by hand. The webbing hole just expands and the washer slips through it. This could be made stronger obviously by just using a bigger washer or stitching the loop to webbing . However with the Kydex backing for rigidity the knife would be harder to draw.

The sheath has a major advantage over traditional khukuri sheaths as the blade can go in either way and you can't get the very dangerous finger limbing that can happen with an improper draw on a traditional sheathref.

UPDATE : the Machax has been discontinued.

Machax, Battle Mistress and Ang Khola khukuri

The Machax was used along side a 18" Ang Khola khukuri (920 g) and a straight handled Battle Mistress from Busse Combat (660 g) . A comparison shot of the three knives :

machax and battle mistress

Chopping

Besides the too obtuse primary grind and edge profile, the Machax is also limited by the curvature which is too extreme and hinders penetration, and increase the tendency to glance when working on large woods. The deep concave curvature of the Machax produces the worst possible geometry for thick wood cutting - a concave profile. To illustrate here is a shot of the Machax on top of a 22" Ang Khola khukuri also from Himalayan Imports :

machax and hi
	khukuri

On some small logs from two to three inches in diameter the performance of the Machax was well under the Battle Mistress and the 18" Ang Khola khukuri. The Machax was slightly more fluid than the Battle Mistress but not enough to overcome the much lower penetration. The khukuri was even more fluid, and overall far more efficient. The relative performance of the Machax increased as the wood sized decreased as on the smaller wood the effect of the extreme curvature of the Machax was diminished.

Splitting some scrap and some small wood two to four inches in diameter the Battle Mistress would bind more readily than the Machax, and the 18" AK easily out split the other two due to its much greater weight and thicker spine. The Bolo influenced top on the Machax was found to be decent for splitting light wood which was layed flat. Chop several holes though ice three to four inches thick, the dropped angle of the Machax made it readily outperform the Battle Mistress. The Ang Khola was again significantly ahead and could easily handle ice that was significantly thicker.

In short, while the Machax has a decent mass and significant forward balance for chopping, it is seriously hampered by a too thick profile, and the extreme curvature seriously limits penetration and increases glances on thick woods. As an aside, the sheath cracked around one of the fasteners when it was forcefully drawn after the blade got stuck inside due to pine sap. A slight crack also formed in the handle during the heavy chopping in the cold.

Slicing and push cuts

For wood carving the Battle Mistress was much more efficient than the Machax due to the thinner and more acute edge and the index finger cutout which allows a choked up grip. The extreme curvature and handle drop of the Machax also makes some common tasks very difficult, food preparation on a cutting board for example. The Ang Khola isn't very functional at these kinds of tasks either for the same reasons and is behind the Machax in cutting binding materials such as cutting thick vegetables because of the much thicker spine.

The Machax is however sightly easier to control and more versatile as a draw knife because of the curvature and the dropped blade and the wide tip which helps with grip. The significantly heavier khukuri is fairly difficult to use for precise slicing work though it does cut well, as a draw knife it is just a little behind the Battle Mistress. In short, the fairly thick edge on the Machax significantly hinders its cutting performance and places it well behind blades like the Battle Mistress which had thinner and more acute edges.

Sharpening, edge retention and edge durability

The edge on the Machax readily rolled and chipped during the chopping. The damage was usually small, about one to two millimeters or wide and about 1/4 to 1/2 as deep. The logs being chopped and split were frozen and knotty. The Battle Mistress and Ang Khola suffered no edge damage during similar work.

Coating durability

After just 250 chops on mostly scrap wood, the coating was worn off from about 1/4" deep in a patch about two inches long. Splitting also quickly remove the coating in flakes and patches, and completely burnished the edge free to a height of about 1/8" deep. This wear and flaking continued at a steady pace as more work was done. Most powder coatings used on blades come off readily but this was the worse seen. After the coating wore back to about 1/2" from the edge the wear slowed down significantly. This was just due to the fact that the forces when cutting or splitting are concentrated at the edge and the top of the primary grind, the middle of the bevel doesn't really see much wear at all.

Grip

The handle has some abrasion problems due to the slabs not being flush with the tang and the deep set hex screws. However the decent thickness of the handle slabs does make for good comfort in general during chopping, splitting and pounding :

machax shbm and ang khola khukuri

Security is also an issue, while the grip isn't as smooth as the handles on the Ontario machetes but it can get slick rather easily. The grip material is however very impact resistant and can handle decent impacts even in cold weather such as beating on it with the spine of the Battle Mistress. While it is not as resistant to open flame as Micarta, it is much more flame proof than Kraton .

General work

To benchmark cutting ability, points were carved on some hardwood stakes which were three quarters of an inch in diameter. The points were one inch long and from three to eight points were made with each knife and the median used as a more robust performance estimate. A medium amount of effort was used during the pointing, and rests were taken every ten cuts to reduce the effect of fatigue. The details :

Number of slices to point a small stake
Model Edge angle Bevel width Distance to cut Performance Ranking
degrees inches inches
Hunter 15 0.016 1.0 17 +/- 1 100
Bolo 19 0.115 1.4 23 +/- 1 74 +/-   5
18" Ang Khola 14 0.350 1.6 23 +/- 1 74 +/-   5
Battle Mistress 16 0.075 1.8 26 +/- 4 65 +/- 11
12" Barteaux 10 0.260 5.1 30 +/- 2 57 +/-   5
Machax 26 0.050 1.0 46 +/- 2 37 +/-   3

It is obvious from the above that the edge angle is very critical, as is the "distance to cut". That distance is the length from the center of the index finger to the first point of contact between the knife and the wood. The greater this quantity the larger the torque disadvantage. The edge width is also a factor in the cutting ability, but has a much smaller influence. The bevel for the Barteaux, khukuri and Battle Mistress are actually convex and thus the very edge is more obtuse but the shoulder is more acute than the angle listed.

The performance on the wood whittling is an indicator in general of how they function on straight push cuts through shallow binding material. On slicing through light vegetation, soft ropes, flesh and other "loose" materials the sharpness can be more critical than the geometry. Gross edge curvature can also play a huge role in such slicing ability and as mentioned above can raise the performance of the Machax over the Battle mistress on slicing through rope due to hooking actions.

The "Bolo" in the above is a prototype from P.J. Turner [ref ].

The Machax and the Battle Mistress were compared extensively in detail. Similar wood cutting was performed over several days on many different types of wood; three quarter inch hickory, one inch pine, and some half inch press board. In total seventeen one inch points were made with each blade. The performance was in agreement with the above with the Machax performing at 64 (4) % of the ability of the Battle mistress. This indicates the Machax takes about 90% more work to point a stake. This aspect of cutting ability was also later explored in more detail including the effect of fatigue.

As a chopper, the performance of the Machax was low for a blade of its size. As noted in the above the Battle Mistress easily out chopped the Machax. The following table lists the median performance of one such comparison which used the blade to chop through thirteen small rounds each :

Wood chopping on small felled logs
Model Mass Balance point Primary grind Edge grind Edge width Ranking
grams cm degrees degrees inches
Battle Mistress 660 8.5 3-4 17 0.090 100
Machax 620 9.5 6-7 24 0.05 - 0.10 64 +/- 4

Though the Machax is balanced slightly more blade heavy, the much thinner profile on the Battle Mistress gives is greater penetration. The Machax did in general bind less which increased its performance slightly from a time required perspective but not nearly enough to overtake the Battle Mistress. In addition as noted in the above, as the wood got larger the performance difference grew even larger in favor of the Battle Mistress.

In regards to technique, these were heavy shoulder driven chops, neither of these blades have enough mass to allow for heavier chopping methods such as drawing from the back legs and hip. The performance of the Machax was very sensitive to impact location. For optimal performance the impact should be at the start of the up-sweep. Too far ahead becomes uncomfortable, similar to hitting a ball on the very top of a bat. Too far back presents a concave surface to the wood which greatly lowers penetration and increase the tendency to glance.

Sharpening, edge retention and durability

The Machax took damage readily in wood chopping through multiple sharpenings. After one short session of about 250 chops the edge took a chip about 0.4 millimeters deep and one millimeter long and three small dents about the same size. Under magnification the dents had started to tear. After the edge had been reground to about 15 or so degrees the Machax showed much better edge durability on hardwoods. On most wood chopping sessions of about 250-500 chops it was rare to see more than one chip or dent.

With the more reduced profile, the Machax was used on cooked bone from chicken, turkey, and beef, and raw moose bone; the edge took no visible damage. The edge was restored with by a simply steeling (10-20 strokes) and some work on a fine ceramic rod (800 grit, 4-6 strokes). The edge was much more durable at the lower angle. While the raw strength had obviously decreased as there was less metal supporting the edge, cuts were more precise, glances were reduced and the edge stress was much lower.

In regards to edge retention during chopping, it was quite below the Battle Mistress. For example after some limbing 1000 chops, the edge was quite blunt. On some 3/8" hemp rope the Machax took about 90-110 cuts to make a cut. When freshly sharp it would only need 3-4 pulls. As for sharpening, the extreme curvature makes clamp and rig system or any kind of guide problematic as it is very difficult to keep the hone perpendicular to the edge. A Sharpmaker or similar system would probably be the best bet if freehand honing isn't an option.

The edge on the Machax was later ground to a lightly convex bevel of about 15 degrees (0.072" x 0.135") to increase the cutting ability. This increased its performance by about 60% in roughing out wood stock. This also increased the chopping performance strongly on shallow cutting on small woods (limbing and such) but on thicker wood (fifty sections such through three to four inches sticks) it saw only a small increase and was at 71 (4) % of the ability of Battle Mistress. Rests were taken frequently to eliminate the effect of fatigue which would increase the advantage of the Battle Mistress.

Durability

The Machax handles heavy tip work well. Splitting, heavy prying and digging in hard woods are not problem. The large cross section from the sabre grinds also makes the blade as a whole decently strong, especially the edge. With just the edge pounded into a tree, the blade easily supported 300+ lbs . The blade was also flexed to over 45 degrees and returned to true. It does however get fairly narrow through the middle so the full blade strength is well behind a wider blades like the Battle Mistress.

Since the blade was going to be returned to Camillus as Will Fennel wanted to examine it because of the edge damage and fast coating wear, the sheath and handle were used for some very heavy work to examine performance in extreme conditions. First the blade and sheath were left in the basement freezer overnight and then tossed across the basement for six feet landing on a concrete floor. The sheath shattered upon impact, losing one major piece and several smaller fragments had broken away . This is the expected behavior of Kydex under such conditions based on personal experience.

The handle was then whacked off of a piece of iron locked in a vice. The impact was between the handle screws where the grip is hollow and a large crack formed with the first hit and the next couple broke a large piece out of the handle. These were very hard swings, full force. Early on it was noticed that one of the rivets on the belt loop bent when the webbing was twisted. With some more twisting and pulling the hole was easily enlarged and then webbing could be completely detached from the rivet. A shot showing the results of the above work :

machax after

Corrosion resistance

The steel does not resist surface corrosion well, but does however not tend to pit. For example after an extended soak in salt water while a lot of surface rust formed:

machax rusted

it all cleaned off easily with just some light scrubbing with a worn Scotchbrite pad leaving some small patches of black oxide, along the edge. The edge had to be completely reground to remove the damaged metal which took less than fifteen minutes.

Grip

As noted in the above there are some ergonomic and security issues. Hard stabs are not possible at all, not enough retention. The surface was lightly sanded (80 grit) but this made little difference as did a file (Leatherman). However use of the Leatherman saw produced a very secure "checkered" grip up there with the most secure grips seen; (Chris Reeves Project and WB from Strider). The blade was much more secure in hand, heavy stabs were possible even with a compromised grip (liquid soap) and chopping glances were also significantly reduced.

However the security of surface texture degraded very rapidly with extended work. The grooves would quickly fill with debris and become smooth and were not deep enough for easy cleaning. The checkering also became smoother as the sharp edges rounded. Limbing out and chopping up up into one foot sections less of than a half a dozen small trees (3-4" at base) made a large difference on the inherent aggression of the surface texture. For a greater lifetime a deeper pattern would need to be cut into the grip instead of just surface scratching from the saw.

Overview

The Machax is an attempt at a modern khukuri style blade however the cutting and chopping ability is hampered by a very thick and obtuse edge. The edge durability is also very low with the initial edge profile and the blade takes damage readily chopping hardwoods. The performance in increased in most respects by adjusting the edge profile however the curvature still has problems with thick wood and the sweet spot for chopping isn't where it should be which is in the upswept portion through the tip.

Solid handle slabs would be far stronger and not prone to storing water and other contaminates. A more aggressive texture on the handle would have benefits for security. The sheath fit to the blade was excessively tight and hindered drawing. Much more durable webbing attachments are also necessary. Thicker Kydex and a folded over style should also be used for greater durability. A decently large finger cutout on the Machax would vastly improve its precision cutting ability but could hinder its functionality as a draw knife as the cutout would remove a decent fraction of the working edge length in that area.

Comments

Comments can be sent to : cliffstamp[REMOVE]@cutleryscience.com. Feedback can be seen in the following archived threads on Bladeforums :

There is also a website for Camillus Cutlery.


Last updated : 04 : 10 : 2006
Originally written : Aug 15 : 2001
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