My last couple of articles have detailed the construction of a Titanium Kukri. If you have not read them, I encourage you to do so to shed some background illumination on this final article.
In this final article, I will briefly discuss the comparative testing that I carried out between my Titanium Kukri and my traditional Steel Kukri. I was very surprised by the results of the testing. In particular, the comparative cutting test. I honestly and sincerely believed that the Steel Kukri would at least marginally outperform the Titanium version in this test. As it turned out, the results were different to what I expected.
As seen in the previous article, the Titanium and Steel Kukris are nearly identical except for a few minor cosmetic differences. The only major differences being the material of construction and the method of handle construction.
For the purposes of these tests, I did not apply the Tungsten Carbide edge treatment to the Titanium Kukri. The Tungsten Carbide treatment creates micro-serrations along the edge which affect the way the blade can be used. Draw-cuts become more effective due to the micro-serrations whereas push-cuts become more difficult since the blade is no longer capable of holding a razor-edge. I have decided to apply this only after the tests because it will affect how the blade performs as opposed to the traditional smooth edge on the Steel Kukri.
As can be seen in the photo at the header of this article, the Steel Kukri is almost identical in dimensions and overall shape to the Titanium Kukri. No small wonder since I essentially copied the design. If anything, the Titanium Kukri blade is slightly thicker at the spine than the Steel Kukri representing a larger overall blade volume.
Both Kukris have the following overall dimensions:
Width of blade at widest point: 5.2cm
Handle Length: 15cm - Titanium Kukri, 14cm - Steel Kukri
Maximum Blade Thickness: 7.3mm - Titanium Kukri, 7mm - Steel Kukri
When I set out to build the Titanium Kukri, I was expecting to produce a Kukri that was literally half the weight of my Steel Kukri. This was not to be, however, due to my decision regarding the handle construction and due to the thickness of the Titanium sheet that I cut the blade from. I opted for a full-width exposed tang and handle scales instead of the pin-type concealed full tang of a traditional Steel Kukri. This certainly increases the overall structural integrity of the knife but there is far more metal in the handle which increases weight considerably. I minimized weight as far as possible by drilling out a lot of material but I was still left with a Kukri that was really only marginally lighter than my Steel one (by about 10 grams).
This happy accident meant that more of the weight of the Ti Kukri was behind the blade when compared with the Steel version. This drastically altered the point of balance of the Ti Kukri. I believe that the altered point of balance had the greatest effect on the performance of the Ti Kukri over the Steel.
The Point of Balance
I believe that this represents the most drastic difference between the Steel and Titanium Kukris. The Steel Kukri has the traditional weight-forward point of balance. This makes it a very effective cleaver if you rely on the weight of the blade to assist with the cuts. The Titanium Kukri has a point of balance which is at the Kukri notch. This is close enough to the handle to be nigh identical to the point of balance for a rapier. The rapier is a very nimble, light sword used in western fencing systems. The point of balance of rapiers is close to the handle in order to facilitate rapid movement and changes in direction. To most users, a point of balance close to the handle of a Kukri would render it less useful as a cutting tool.
The Cutting Tests
As mentioned earlier, in order to do a good comparison between the cutting capacity of both Kukris, I did not apply the Tungsten Carbide edge treatment to the Titanium Kukri. The Titanium Kukri thus has a softer edge when compared with the Steel. In the cutting tests, both Kukris were sharpened between tests.
The first test was a comparison of cutting capacity when cutting paper. There is no real science to this apart from demonstrating that both Kukris were approximately the same level of sharpness. The Steel Kukri was possibly marginally sharper.
The second cutting test was testing the capacity for both Kukris to cut through a standard MGP10 70mm by 35mm pine batten. The test was not timed since speed and reaction time of the blade were not being tested here. Instead, I allowed myself a maximum of 20 strokes per Kukri and then compared the depth of the notches produced. This test was performed only once for each Kukri before a comparison was made. I tried to make the test as impartial as possible although it was difficult as I was using a different technique to produce force with the Ti Kukri. I had to ensure that my bridging and kinetic chain mechanics were engaged at all times during the Ti Kukri testing since I could not rely on the weight of the weapon to do the work for me.
Although I tried to be impartial with this test, I was so surprised after the first couple of strokes with the Steel Kukri due to the increased level of cutting difficulty, that I believe I may have increased the amount of force I was putting into the last few swings. I even accidentally used more than 20 strokes for the Steel test. Despite this, the Ti Kukri outperformed the Steel.
Another factor which may have altered the outcome of this test was that during the Steel Kukri cutting test, the pine batten split down the middle and this split may have acted as a minor shock-absorber which could have accounted for some of the performance drop-off for the Steel Kukri. Even so, taking this into account, I feel that the Ti Kukri cut far easier and deeper than the Steel Kukri.
I’m not 100% sure why there was this unexpected disparity. Perhaps the nimbler Ti Kukri was easier to land accurately in terms of placement and edge alignment to more efficiently cut through the pine.
At the end of the day, all tests of this nature are subjective to a certain degree. The more you become involved in the testing procedure, the more of an effect you can be said to have on the outcome. As can be seen from the video footage, the Titanium Kukri marginally outperformed the Steel Kukri despite the different point of balance. I was most surprised about this. I certainly did not expect it.
The Speed and Reaction Tests
The speed and reaction tests were recorded and then timed in video editing software. We estimate that the margin for error is approximately 0.015s.
The first speed and reaction test involved making a series of cuts at a set of three hanging expanded-polystyrene balls between 6 cm and 7 cm in diameter to show speed of transition from one target to another. Although my overall body rotation could be used to power each of the three cuts, each cut had to be distinct. In other words, I would not use a single sweeping cut to engage all three targets. In order to minimize my involvement as far as movement was concerned, I maintained a stationary stance and changed targets without moving. This test was timed and performed three times with each knife to compare the averages.
The averages were as follows:
Average time between the first and second strike: Titanium Kukri - 0.36s, Steel Kukri - o.36s
Average time between the second and third strike: Titanium Kukri - 0.32s, Steel Kukri - 0.33s
It was interesting to note the consistency of speed through all of the ball strikes. Every single time between the first and second strike was 0.36s, every single time between the second and third strike was 0.33s except for one of the Titanium Kukri strikes which was 0.30s. This leads me to believe that I was subconsciously trying to ‘standardize’ the tests. As can be seen from the footage and the averages, the Ti Kukri did not show a significant advantage in this test perhaps due to my overall involvement in the movement.
The second test involved changing undercut orientation mid stroke from left to right. This basic technique can be used in various orientations to capture, parry or change attack lines. This test was also timed and performed over three iterations to compare the averages. It is in this test the Ti Kukri showed the biggest advantage over the Steel Kukri.
The averages were as follows:
Average time between first and second undercut strike: Titanium Kukri - 0.25s, Steel Kukri - 0.35s
This is a hugely significant result! The Titanium Kukri was nearly 30% faster in this test than the Steel Kukri.
The Fun Stuff
Just for fun, I did some cutting of water bottles and soda cans with the Titanium Kukri.
As mentioned earlier, it was really difficult in this series of tests to maintain objectivity and standardisation because of the differences in my methods of force generation. As such, it is hardly fair of me to say that the tests proved anything categorically. What I will say is that the Ti Kukri feels like a precision razor which can strike hard whereas by comparison, the Steel Kukri feels slower and more cumbersome. I was very surprised with the cutting effectiveness of the Titanium Kukri.
At least as far as I’m concerned, the testing has proved that with the correct internal body mechanics of the wielder, similar cutting results can be obtained for a Kukri with a much nimbler point of balance. The weight forward design is not strictly necessary to get cleaver-like results from a weapon. This does require considerably more training investment and instruction from teachers who know what they are doing as far as these internal training methods are concerned.
I believe that the nimbler Ti Kukri design allows for faster and more fluid movement of the weapon, turning it into the epitome of Muhammad Ali’s famous quote, “Float like a butterfly, sting like a bee.” I’ve had a lot of fun building and testing the Titanium Kukri and I am very happy to own this beautiful weapon. For all those Tolkien fans out there, this is about as close as you will get in the real world to the handling and physical characteristics of a Mithril weapon. I look forward to passing it on to my son when the time comes.
Written by SiFu Lester Walters, head of the Chinese Martial Arts and Health Centre Australia
© Chinese Martial Arts and Health Centre Australia 2017. ABN 12 792 347 015