Introduction: Leaf Spring to Gurkha Khukri

Picture of Leaf Spring to Gurkha Khukri

The kukri is a large knife, originating in Nepal, the national knife. The kukri is as iconic in that region, as the Bowie knife to western culture. It's a multipurpose knife, with a history or brutal efficiency. It was carried by every Gurkha soldier as a last resort weapon. They were kept razor sharp, and sliced through enemies with ease. They developed a legend around themselves. It was symbolic of the soldiers. There are kukris in museums dated at over 500 years old. The knife may be even older, with connections to the classic Greek sword Kopis. It's a core part of the nations history, even well known to most of the world.

The blade has a curve on the front as well as extra mass for a heavier weight. Another interesting point on the construction on a typical kukri is the notches on the blade, similar to a choil. However they say it stops the blood from dripping onto ones hand. This protects once grip, and increases longevity of the handle. The knife also has two other small knives associated. They are either in the sheath or in a separate case. They are called Karda and Chakmak. The Karda is a small utility blade, and thr Chakmak is a blade for sharpening.

I wanted to recreate the kukri in a way that pleased me. I was looking for a more hefty construction, not accurate to history. I also have a different curve and head size. I probably won't be making the small knives either. Regardless, I have always been intrigued by this Nepalese knife, and wanted one of my own. Let's get started, shall we?

Step 1: Type of Steel

Picture of Type of Steel

I have really enjoyed using steel leaf springs for knives and swords. If I'm not mistaken it is typically 5160 steel. It's a fairly easily workable metal, with good strength.

For this machete I started with about an 18 inch section. I cut off the holes, and started forging. I then marked out the dimension of the piece on the table, and drew a finished goal to reference.

Step 2: Forging

Picture of Forging

I didn't get very many pictures of this part, but anyways.

I started by hammering the front down to a point. I simply lined up the tip toward the side of the anvil and started smashing away.

The kukri has a much heavy portion toward the front of the blade, so I started hammering the sections prior to that.

With each few hits, I had to flatten the piece again, since the edges would thicken up with each blow. It made for a very long process since I needed to make it about half as wide as it was initially.

Hammer after hammer.

The blade wasn't pointing down far enough, so I had to grind it down to shape. Halfway through, when I did that, I also ground the profile to a closer shape, before returning to forging.

I continued stretching out the thin portion of the blade and the handle. With it all sized down I hammered out the belly of the handle and rounded the back of the handle.

To divide the spot between the blade and the handle I forged a choil.

Step 3: Drilling

Picture of Drilling

Drilling holes can be very challenging. Different types of steel harden in different conditions.

Some steels will harden some just by cooling off in the air. Others may harden from a splash of water.

Another issue is work hardening. By forging the steel, it may build up a hardness even though it wasn't quenched.

When I drilled these holes, I was having trouble. I had to anneal the steel. Annealing is heating up the blade to critical temperature and letting it cool very slowly to relief hardness and stress from the steel.

I used three cycles of heat and cool. I let it cool in a fireproof insulating environment.

I drilled the holes first with a smaller drill bit. Before I annealed it I broke a drill bit in the handle. I resorted to drilling different holes and having some holes run though the blade for glue.

Step 4: Grinding

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I have never ground a bevel that had an inward curve. You can't use the flat surface of the grinder like typically (At least as easy). I opted to to use the larger wheel on the bottom to do all the grinding.

I started with a steeper angle until I reached about the middle of the blade thickness minus the middle 1/16 in. Following that i gradually decreased the angle, by cutting farther up the blade.

I started by grinding the whole edge, top to bottom. As I got closer to finish I would grind smaller portions, focusing on evening everything out.

Near the base of the grind it was thicker, caused by the curve of the wheel. Ideally, its an issue, but has no major issues.

I cleaned up the grind with a flap wheel on the angle grinder. It makes quick work, and looks good. I also used it to fix the cutting edge/bevels.

I went to the scotch brite belt and cleaned the whole thing.

On to heat treat (HT)

Step 5: HT

Picture of HT

Heat treating is synonymous with quenching and hardening.

It is aligning/locking the carbon atoms in the steel by cooling it at the proper speed. Some steels use oil, others water, air, or soapy combinations.

I generally use oil, as it's a safe guess that people typically have luck with. I have used it on leaf spring, and it seems to do well. I need to do a stress test on a blade at some point, I'll make a video.

I quenched in a bucket of oil, and used the scotch brite belt to clean it up. Then I applied some beeswax after slight heat.

Step 6: Cut and Glue

Picture of Cut and Glue

First you gotta select your wood. I used some section of wood I had in my box.

I marked the approximate size with a sharpie. I cut it out with the table saw. I cut the piece in half to make the scales. I then lined up the scales with the front of the handle section. I marked the spot in the hole for the pin with a punch.

I drilled the hole on the spot. The pictures show the process pretty well. Next I put it the pin through the blade and the scale with the hole. With them held together, I drilled through the other hole of the metal, to drill into to scale.

For the other scale's holes:

I marked the hole with a punch the same way as with the first one. I drilled out the hole. I then used one pin to line up the scales with the blade, and marked the next spot, through the other sides holes. I drilled it out.

I checked the fit and moved on

Step 7: Preglue Shaping

Picture of Preglue Shaping

The hardest part to shape on a knife handle is the front edge toward the blade. Because of this, I find it essential to shape that first.

I just used 80 grit paper to put a radius on the front. Reference pictures for size.

With the front shaped, its time to glue.

Step 8: Gluing

Picture of Gluing

I glue everything together with a two part epoxy from harbor freight. I used the saw dust from the last step to color the glue. I had beeswax on the handle so I sanded this off. I slathered all surfaces, including the pins. I pressed them together using a vise. A few clamps can be used as well.

Now for my minor innovation
I always have the pins be a bit wider then the scales. These get in the way when I try to clamp it all in the vise. I got around this by drilling holes in a couple boards, and letting them grip the kukri. This allows the pins to go through and apply pressure instead on the scales. This ensures a solid gluing. I let the glue cure for a few hours.

Step 9: Handle Shaping

Picture of Handle Shaping

Step 10: Finished

Picture of Finished

There you have it. Please use the comments, let'em fly

Happy Crafting

BC

Comments

CJStephens (author)2015-07-16

Great blade! the khukri is one of my favorite style of blades its so versatile and has many uses. you did an out standing job on the handle as well.

spark master (author)2015-05-11

sweet, love the handle, I'd bet it would make a formidable hunting boomerang. Of course if one missed.....

Jislizard (author)spark master2015-05-11

With the weight of these things I don't think you need to worry about being decapitated on the return. Maybe just a long walk to collect it :)

From the maintenance page in the website of the company who make Kukris for the Gurkha Regiment...

http://www.khukurihouseonline.com/Content/Catalog/...

FACT: A Kukri is not a throwing knife so should never be thrown.

SOLUTION: Don't throw

There is a section on how to straighten out the tip though...

spark master (author)Jislizard2015-05-12

A hunting boomer is not a returning boomer, It goes out into a flock of birds etc, and simple wacks one of many, think shotgun. They can kill, but can just incapacitate. I have wacked single rabbits with them in my yard. This solves the problems of coupe de gras. You can bring down an animal, but not kill it, and then you must cut it's throat or snap it's neck. This will not have the problem (I do say this as a joke btw, I would never toss one of these, that would be silly and insane).

If you threw it in battle someone could pick it up then pick you off with it.

Jislizard (author)spark master2015-05-12

Thanks for the clarification on boomerang types, most of my boomerang knowledge comes from cartoons :) . I thought the idea of a boomerang was if you threw it and missed you didn't have to go on a trek to pick it up, but if you hit something you had to go out into the field to pick up your prey and at the same time you retrieve your boomerang.

MakeBromyard (author)Jislizard2015-06-01

Not quite. There are hunting boomerangs and throwing boomerangs, and the they different. Throwing ones are to practise your throwing, strengthening your arm and the like, so that you don't need to walk so far to fetch it. Hunting ones are far heavier and are not designed to come back, because they'll break your arm.

shantinath1000 (author)2015-05-13

Well done!

DickB3 (author)2015-05-13

Instead of drilling you could hot punch the holes in the handle. Thee are lots of videos on the internet showing how to do it. You should be able to punch small holes (1/8 to 1/4 inch) through 3/8 inch leaf springs in less than 5 minutes. You can make the punch from automobile coil springs or tire irons or crow bars. Heat treating is not needed. I've even made punches out of rebar or mild steel. Be careful to keep the work hot and the punch cool.

dung0beetle (author)2015-05-12

The raised ring near the middle of the Khukri handle allow for a non-slip grip when thrusting. This is necessary because there is no guard present. This is an often ignored design element in modern replicas. (I understand you were not aiming for historical accuracy, but it is a very useful feature.)

Arghus (author)2015-05-12

damn it i want one!!

dmhagenjr (author)2015-05-10

Okay, here's mine to you, and to the group as a whole, if anyone has any experience of this sort.

I'd like to do this, but wrap the handle in paracord. I thought of cutting a slat, lengthwise, in the handle, and then do a figure eight wrap with the cord around the outside and through the middle.

Now: Would this affect the structural integrity of the handle/knife? And, if it does, is there a hammering or tempering solution?

Hey sooo I finished. Ible in a day or two

That would definitely work. I might make a stock removal machete and try it out for a test run. Thanks for the idea -BC

Oaky, well, that'll be a fiver, payable by PayPal. Thank you very much.
But, yeah, I'm a neophyte to metalwork, with the forging, and didn't want to waste time and material for something that would ruin the structure's hardiness.

Offering money? Lol. Does that mean you'd be interested in purchasing the final build? Your idea gets a discount ;) Or was it a joke lol. Self promotion is all

Jislizard (author)dmhagenjr2015-05-10

Check out the Turk's Head Knot. This will go over the top of the handle so no need to cut at all. It is not easy to undo if you were thinking of being able to use the paracord for an emergency but on the plus side, if the cord does get cut, the whole thing won't unravel leaving you with a next to useless machete.

dmhagenjr (author)Jislizard2015-05-11

Actually, I like a Strider wrap with the bump on the inside, toward my palm, but I like to use a skeleton handle with it. So, I was wondering about the strength of the knife, or degradation thereof, by cutting a slot down the middle of a kukri's tang.
I think that a modified turk's would be useful as well, and I'm going to play with one with a leather cord in too, just for the look.

Jislizard (author)dmhagenjr2015-05-11

What I can remember from looking at the traditional kukris, they had a rat tail tang anyway. So if you have a full tang with a slot you will still have more metal in the handle than most kukris in use.

tomasihvon (author)2015-05-10

Okay, as a blade enthusiast, I cannot let misinformation go uncorrected. The groove on the blade has ABSOLUTELY NOTHING to do with blood or protecting grip or anything of the sort. The grooves are there as a way to increase the strength of the blade itself by increasing the area of the cross section while simultaneously reducing the amount of material needed to be as large of a blade. That is all.

-steps off of soapbox, lol-

Hey, yes I understand that. You mistook my statement. I was referring to this notch. No harm done, alot of people make the blood groove mistake. The traditional kukris have two notches with a peg in between the two.

Jislizard (author)2015-05-10

Nice instructable, making a kukri was the reason I started blacksmithing, which I must get around to doing one day.

The angle between the handle and the blade on the traditional shaped kukris served a very useful purpose. You could hold the kukri in front of you in a fairly comfortable grip, the way you would point a fist at an opponent, and the pointy bit would be directly at them. So punching an opponent with a kukri in your hand would result in the kukri going in pointy end first. With a more traditional knife you would have to over extend your wrist forward to stab them.

When not stabbing people you could chop wood and once again, the angle helped. Getting the head of a more traditional axe to cut requires extending the wrist a lot further than using the kukri, causing more fatigue in the wrist.

Wow, see I continue to learn. I've liked the way it chops, but never quite knew why. Thanks for sharing. Punching is good too

bevin.chu (author)2015-05-10

Does the curve in leaf springs make it hard to create a perfectly flat blade?

Does the leaf spring have any tendency to revert to its original curved shape even after being flattened?

I ask this because I really like the idea of recycling leaf springs this way, and wondered whether the built in curvature was a problem or not.

Annealing the steel helps to take out this tendency to revert to the curved shape. I found that it wasn't even needed in fact. I just heated it up, and smashed it flat. Leaf springs ate phenomenal for blades.

Thanks for sharing that. Learned something new. Always assumed it would be problem.

tomasihvon (author)bevin.chu2015-05-10

Once you heat the spring to a nice glowing red/orange and hammer it flat, it will stay that way. Any changes you make to metal after heating and hammering will stay that way until you do the process over.

bevin.chu (author)tomasihvon2015-05-11

I see! Very interesting. Thanks!

nkz75 (author)2015-05-07

Great job!

Tell me one thing, as I am planning on doing one to....

We you swing the knife doesn't it tries to slip out of your hand due to the extra mass? I'll probably try to make threaded grip?? What do you think of the idea!!???

Best regards!

Jislizard (author)nkz752015-05-10

The threaded grip will also help prevent your hand from slipping off the handle onto the blade during a thrust into something solid. Kukri handles can have a small ring around the middle, this is also to prevent the hand slipping forward, I thought it was just decorative but apparently not.

dmhagenjr (author)nkz752015-05-10

I carried a Kukri into combat during the one operation I got to do before being medically retired. The traditional handles tend to be curved hourglass shapes, and the broader part on the bottom creates a backstop to the centrifugal force from the swing. I asked a question about a paracord handle, and plan to make a bulky knotty bit (very technical term) on the bottom of the hilt.

nwlaurie (author)nkz752015-05-10

A Nepalese Kukri has the grip flared at the outer end precisely to help with slippage prevention.

A Kukri is a heavy knife and apart from the iconic beheadings and suchlike, it is typically used as a workshop tool and – even more commonly – a general-purpose garden tool. The flared grip helps when the hands get tired!

Basement_Craftsman (author)nkz752015-05-07

The extra mass doesn't have too much effect on holding it. Although the threaded grip would be a neat design.

Brutus Ultimatum (author)2015-05-10

Nice work and instructable, looks cool!

dmhagenjr (author)2015-05-10

Oh, and, very cool build.

Mjollnir1907 (author)2015-05-10

Excellent job!

ShopHazard (author)2015-05-07

That's a nice-looking handle.

neopolitan (author)2015-05-06

love it. a pattern for the blade would be awesome. Im new to knife making - do you think if i use stainless it would need heat treating or is stainless not the right material for this ? i have a lovely piece of 4mm that is crying to be made one of these...

The best piece of advice I have for you is to simply try it out. Most types of steel will require a HT. Like vonronge says, there are many types of stainless

vonronge (author)neopolitan2015-05-07

There are hundreds of kinds of "stainless". Which one are you thinking of using? 17Cr-4Ni is good, but needs precipitation hardening. 440C is a good choice. If you plan on lots of grinding, 440F.

vonronge (author)2015-05-07

Nice!

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