Khukuri Specs Issue: OAL vs Weight

mohd

mohd

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Jun 3, 1999
Messages
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The main issue which I want to rise here is whether there should be any incremental ratio in the increase of weight with the increase of OAL.

I take AK model as a sample here: Since the registered weight of 15" OAL AK is 1.5 lbs; what do you think the suppose to be correct weights of various OAL AK with average length increment of 3" each?
  1. 9" OAL AK = ? lbs.
  2. 12" OAL AK = ? lbs.
  3. 15" OAL AK = 1.5 bs as the standard.
  4. 18" OAL AK = ? lbs.
  5. 21" OAL AK = ? lbs.
  6. 24" OAL AK = ? lbs.
  7. 27" OAL AK = ? lbs.
  8. 30" OAL AK = ? lbs.
  9. 33" OAL AK = ? lbs.
  10. 36" OAL AK = ? lbs.[/list=a]Pakcik Bill & Forumites.

    If 15" AK is 1.5 lbs, 18" AK is 2.5lbs and 21" AK is 3.5 lbs! - this means length increment of 3" will increase it's weight for 1 lb! - then this means 36" AK will have a weight of 8.5 lbs! ... ISN'T IT TOO MUCH WEIGHT FOR A KHUKURI?

    What do you say about it?
    Do you have any specs formulation that can derive what suppose to be the correct weight for the various OAL of the above example?

    NEPAL HO!

    [This message has been edited by mohd (edited 06-21-2000).]
 
While weight is linear in length, it is also linear in thickness and width. When you increase the length of a khukuri by say 25% the weight will not go up by only 25% as the thickness has to change as well and probably the width. If you left the thickness the same the khukuri would be weaker because it would not be able to take the greater torque. The greater width allows a similar edge profile with the thicker spine.

Some weights for Ak's (mine) :

15 : 680 g

18 : 920 g

22 : 1700 g

The 22" weight is an estimate based on a weight I have recorded on an imprecise scale of 3.75 lbs, which should be within the real weight give or take .25 of a lbs. I never got around to measuring it more precisely. In any case you can see that the weight goes up much faster than the percentage in crease in length (it is more like that to a power of 2-3).


-Cliff
 
Mohd,

Since weight is proportional to volume, if the relative dimensions are kept constant the weight will vary as the cube of the linear dimension. Using the 15" AK as a base and figuring the ratios I get:

1. 9" OAL AK = 0.32 lbs.
2. 12" OAL AK = 0.77 lbs.
3. 15" OAL AK = 1.5 bs as the standard.
4. 18" OAL AK = 2.6 lbs.
5. 21" OAL AK = 4.1 lbs.
6. 24" OAL AK = 6.1 lbs.
7. 27" OAL AK = 8.7 lbs.
8. 30" OAL AK = 12 lbs.
9. 33" OAL AK = 16 lbs.
10. 36" OAL AK = 21 lbs.

This illustrates that it is not practical to keep the proportions invariant as the knife is scaled up. I suspect that is what happened to the MegaSalyan.

As to what the proper proportions are, that should lead to some good arguments. I think that as the lever arm on the longer blades increases, the need for weight becomes less to get equivalent chopping performance. What weight there is should be towards the tip to maximize the blade's moment of inertia about an axis through the handle and perpendicular to it. My WWII achieves this with a thin waist and a bulbous tip.

Then again, for thrusting a pointed tip is preferred. And for prying lateral strength is important. As each use is emphasized or de-emphasized the ideal proportions change. Maybe that is why there are so many styles, and we spend so much time trying to find the "perfect" style for our own, highly personal, mix of uses.
 
I`ll leave the physics to the qualified.I have noticed that what you get is only about what you ordered.A 20" has been 22",even 23".Only one was 1/2" short.

Specs don`t really matter to kami`s.They want enough, but if the steel wants to stretch; that`s OK.They are not going to grind it down.With Brit issue, they stick to specs.Anything else,you get what they want to give you.

This is not bad.Armies need uniformity.We usually don`t.

On the sarki question; I don`t think that they believe that any but Gurkhas actually wear these things.The BAS scabbards and frogs are interchangable and good to go.We know about the others.

Bill is kind enough to send you a BAS frog if you want to wear the thing.When that paper loop rips out; change it out.You know that these belt loops are not going to support 5# for long.
 
I have to agree about the kamis. In general they will make what THEY think is appropriate for a given style of khukuri.

Note the thickness and weight of some of the larger Ang Khola models. As these are choppers, it certainly doesn't hurt to have that extra weight.

Now check out the Kobras - 18-20 inch models, these are quite thin as compared to the AKs previously mentioned.Incidentally, for those who have examples by Kumar and Sanu and Bura, have you noticed any differences in thickness and weight?

Bottomline, the kamis have many different styles available to choose from. Sometimes they humour us by creatively altering our desired designs, and for the most part, I think this has worked out well.

Harry
 
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