best quenching process for khukris

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APS89

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What's the best quenching process to produce strong khukris which can cut nails without damaging the edge?
 
An overall heat treating process or specifically just the quench? What steel? Have you made a knife before?
 
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It's going to depend on the steel type what quench is best.
Edge geometry will also play a big part in cutting nails without damage.

A knife I made which had edge geometry similar to what would be seen on a kukri was 5160 steel at 57 Rockwell, which is what I wanted it at.
Heat treated by McLearie & Sons Heat Treating; they use salt heating and salt quench mainly.

A friend was splitting a 2x8 plank with it (lengthwise, by chopping), and it had a nail in it.
Found that out when the knife chopped through it and we saw the spark.
Very minimal nick on the edge (had to look closely), and the edge was sharp enough to shave arm hair just prior to the chop.

Certain other steels could handle that a bit better, but I never intentionally chop nails. ;)
 
Are you making a cold chisel or a knife? They have quite different edge geometry

Heat treating processes are broadly determined by steel choice. So start with what steel you're using and go from there. For a larger chopping knife like a kukri you'll probably want something like 5160 or 80crv2 (I don't know about stainless options)
 
I personally use a hack saw to cut nails and a knife to cut wood and food.

If all your earlier research on Kukris last year didn't get you what you wanted:
The Kukri was designed to be a utility weapon for fighting and a camp knife when needed for everything else. Nails were never part of that design.
Knives cutting nails is a sales trick. It is done by grinding a thick edge that is not very sharp. This is basically the edge on a cold chisel. Most any knife with a thick blade can be sharpened to cut a soft iron nail. "Nail cutting knives" are usually much softer than user knives. They often are in the low Rc50's.

The edge on a kukri is ground thick to allow striking bone and hard wood but is sharpened to a fine edge. The edge is often convex to give it more stability in heavy use. The traditional steel is 1055, which has a high manganese and medium carbon content. It hardens to around Rc55, which is hard enough to survive most any blow and can be easily sharpened. This makes a very tough blade.
Many modern kukris are from a simple steel between 1060 and 1080. Quenching should be as normal for the steel used. What happens in the quench that is different than a thinner/smaller knife is that the thick upper bevels will not harden as deeply as the edge. This makes the kukri much tougher in very hard chopping or when striking armor or another steel weapon.
Another popular steel for a kukri is a chromium toughened steel like 5160.
 
Lorien said:
you'll have best results using cast iron, quenched in tiger urine.
Click to expand...
That will only cut soft nails, for hardened nails you need to use meteorite steel and quench on full moon night in a mountain stream.

On a serious topic, research what nathan the machinist does with 3v for very tough knifes. There is many other tough steels, but it will depend greatly on the ht and the geometry of the grind. Other then that knife are not made for cutting nails.
 
FredyCro said:
That will only cut soft nails, for hardened nails you need to use meteorite steel and quench on full moon night in a mountain stream.

On a serious topic, research what nathan the machinist does with 3v for very tough knifes. There is many other tough steels, but it will depend greatly on the ht and the geometry of the grind. Other then that knife are not made for cutting nails.
Click to expand...
the upcoming CPK Khukuri will cut nails. Might even cut a car in half.
 
I am not a bladesmith. I am just curious.

Top Nepali khukri makers make nail cutting videos these days. I think they use 5160 steel

What the best heat treatment / quenching protocol for a khukri?
 
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Stacy E. Apelt - Bladesmith said:
I personally use a hack saw to cut nails and a knife to cut wood and food.

If all your earlier research on Kukris last year didn't get you what you wanted:
The Kukri was designed to be a utility weapon for fighting and a camp knife when needed for everything else. Nails were never part of that design.
Knives cutting nails is a sales trick. It is done by grinding a thick edge that is not very sharp. This is basically the edge on a cold chisel. Most any knife with a thick blade can be sharpened to cut a soft iron nail. "Nail cutting knives" are usually much softer than user knives. They often are in the low Rc50's.

The edge on a kukri is ground thick to allow striking bone and hard wood but is sharpened to a fine edge. The edge is often convex to give it more stability in heavy use. The traditional steel is 1055, which has a high manganese and medium carbon content. It hardens to around Rc55, which is hard enough to survive most any blow and can be easily sharpened. This makes a very tough blade.
Many modern kukris are from a simple steel between 1060 and 1080. Quenching should be as normal for the steel used. What happens in the quench that is different than a thinner/smaller knife is that the thick upper bevels will not harden as deeply as the edge. This makes the kukri much tougher in very hard chopping or when striking armor or another steel weapon.
Another popular steel for a kukri is a chromium toughened steel like 5160.
Click to expand...
Very informative post. Thanks
 
Tasmanian Tiger urine was the best but is hard to get anymore. It is rumored that the Nepali bladesmiths desire to attain it led to the extinction.
 
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