Zone hardening question

StrangeDaze

StrangeDaze

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Mar 20, 2016
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hey everyone. I just ordered my first HI kukri and am excited to recieve it. I was reading around and it appears they are zone hardened, leaving the tip and blade closest to the handle “soft”. I am just wondering to what degree? Is it very soft, unhardened even? Or is it just a few degrees softer than the belly? If i use the “soft” part for making something like a feather stick, will it dull quickly? I realize they come with a smaller knife that is more useful for such tasks so it is not really an issue. I am just curious. I will find out soon enough i guess but wanted to know what i am in for.
 
You pretty much got it figured out it seems. Grats on your first HI Khuk! The re-curve part and tip is softer however, it is hardened to some degree. What wears down quickly also sharpens quickly. The little knife without the edge (Chakma) is used to keep the edges burnished and works very well for all the small dings. The recurve part of the blade is great for making feather sticks and such. Also makes a great draw knife. There's a gazillion post on sharpening so you should have plenty of reading. Prolly the most covered topic here other than curved spines and mules;) Somewhere there is a drawing showing the basic zones of hardening. If I can find it again ill link it. What model did you get?
 
ndoghouse said:
You pretty much got it figured out it seems. Grats on your first HI Khuk! The re-curve part and tip is softer however, it is hardened to some degree. What wears down quickly also sharpens quickly. The little knife without the edge (Chakma) is used to keep the edges burnished and works very well for all the small dings. The recurve part of the blade is great for making feather sticks and such. Also makes a great draw knife. There's a gazillion post on sharpening so you should have plenty of reading. Prolly the most covered topic here other than curved spines and mules;) Somewhere there is a drawing showing the basic zones of hardening. If I can find it again ill link it. What model did you get?
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I got the used wwii model that was up recently. Seemed like a good place to start.
 
My brother has some hardness testing files that we played around with on my HI blades. Every one of them was between 55 and 60 Rockwell Hardness in the chopping zone. They went down to between 40 to 50 at the tip and toward the cho. There were 3 blade edges that were harder that 65. They were a Tarwar by Bura, a Balance Knife by Naubin Rai, and a Parewa Knife made by Ram Kumar. Those also happen to be some of my favorites. The Tarwar sleeps on my wife's dresser. The Balance Knife Khukuri stays in my car, and the Parewa knife (I call it "Gift Knife" since Yangdu gave it to me) is always in my backpack for when I need it. I like it for carving, food prep, and general utility. I gutted and skinned my last deer with it. The Balance Knife and Gift Knife come with me every time I go hunting or camping. All of these knives retain an edge very well.

I also have a Kumar Utility Villager Khukuri that has a hard chopping spot and a very soft tip. I can sharpen that tip to a razor with just the chakma. A soft tip on a khuk can be a very good thing. Your WWII probably has a very stout tip. The softer parts are not going to bend or fold. They will dull easier if you are chopping very hard wood with them. The best way to avoid that is to practice and find the chopping sweet spot. Use the hard part for chopping and use the softer parts for slicing. I have cut down a 7" wide tree and then immediately sliced tomatoes.
Edit: I just realized that you posted about the flat edge tip knife. I guess this one will be heading back to Reno. My First HI purchase had 2 knives from Kumar. One is still my tried true, go-to work horse. The other had a heat treat issue and the edge folded over. That didn't stop me from buying many more. I have had 4 knives total with heat treat problems. 4 out of 40 isn't bad considering they were all sold as blems. Each time Yangdu took good care of me. I always ended up with something better than I originally paid for or of higher value. Her service and the knives with magic in them kept me coming back for more.
 
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If your WWII is going to be a user and you want to check out the heat treatment profile (hamon) you can rub some lemon juice across the edge and the line will show up. Depending on what type of stuff your chopping it will sometimes show up anyway. Interesting to try the hardness files but I havent done that. I dont think ive ever chipped an edge on an HI blade as far as I can remember but then again I cant remember crap anyway:). Thanks for the input Eric. I always suspected your findings but I have yet to buy me a file set. Someday id like to do that? In general id rather have my blades on the softer side for field serviceable reasons. One exception is fish filet knives. I like them hard and sometimes hard as flint.
 
I just got back from fishin for a couple weeks. I'd love a fillet knife that stays sharp.
For some reason I can't get them buggers sharp to save my backside.
My fishin pard has one of them electric fillet knives, had it a few years. I'll be having me one for next year. Works great. Still need a sharp knife.
 
Yep those electric ones work good if your home or around electricity but im not that fortunate most of the time. I suppose they prolly make a rechargeable electric dont they? Ive never seen one but one would think they exist. How did you trip go? Did ya catch anything?
 
ndoghouse said:
If your WWII is going to be a user and you want to check out the heat treatment profile (hamon) you can rub some lemon juice across the edge and the line will show up. Depending on what type of stuff your chopping it will sometimes show up anyway. Interesting to try the hardness files but I havent done that. I dont think ive ever chipped an edge on an HI blade as far as I can remember but then again I cant remember crap anyway:). Thanks for the input Eric. I always suspected your findings but I have yet to buy me a file set. Someday id like to do that? In general id rather have my blades on the softer side for field serviceable reasons. One exception is fish filet knives. I like them hard and sometimes hard as flint.
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I've never tried the lemon juice trick. I will check that out. My brother has a forge and I am working on blacksmithing my first knife by myself. I cannot believe the time and effort it takes. The knife I'm working on is just a tiny one. Annealing, shaping, normalizing, hardening, tempering. All that and fitting a handle and finishing the whole thing! I feel like I am only beginning to understand the time, effort, skill, and heart that goes into each knife. It boggles the mind that they could complete one of these in a day. They are indeed magicians.
 
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Show us your progress Eric! Id love to check it out. Ive only made and finished one knife completely and it is gratifying to say the least. I made two at the same time but one developed a crack right across the middle. I think I let it get a bit too cool. Doing the flex/bend test is nerve racking to say the least. I figured id snap it right there but it survived. Makes you really appreciate them multi fullered knives dont it?
 
ndoghouse said:
Show us your progress Eric! Id love to check it out. Ive only made and finished one knife completely and it is gratifying to say the least. I made two at the same time but one developed a crack right across the middle. I think I let it get a bit too cool. Doing the flex/bend test is nerve racking to say the least. I figured id snap it right there but it survived. Makes you really appreciate them multi fullered knives dont it?
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I cannot even comprehend the HI kami's skill level. I'll post something in the Cantina and put a link below:
https://www.bladeforums.com/threads/forging-a-knife.1676061/
 
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Bawanna said:
I just got back from fishin for a couple weeks. I'd love a fillet knife that stays sharp.
For some reason I can't get them buggers sharp to save my backside.
My fishin pard has one of them electric fillet knives, had it a few years. I'll be having me one for next year. Works great. Still need a sharp knife.
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Have you ever played with the nordic fishing knives? Some of them will take hair off your arm as soon as look at them and will hold that edge. I agree that the american style fillet knives are not much better than tin in that regard.
 
I like those Nordic knives alot. I made me one from a file and its hair poppin too. I think I got lucky tempering it too. Beginners luck might say. IIRC Repala made them for many years in a leather covered sheath.

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On the original question about how soft/hard HI blades are near the tip:

I bought an HI Seax last year that came with the tip slightly bent to one side. I decided to try straightening the tip by banging it sideways against a block of wood.

The HI Seax has a pretty thin tip -- thinner than most HI models -- but it took a couple of dozen very hard bangs against the wood to straighten it out. I don't know about the hardness, but I guess that speaks to the toughness of the steel near the tip.
 
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