Steel baptised by raging flames

golok

golok

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Oct 20, 2000
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I have just returned from a trip to a small town located in the boondocks. The only interesting thing about the place is this shop where the guy makes knives and other cutting tools.

I bought a spring steel blade from this middle-aged chap. And he said quite matter-of-factly that in order to achieve its "unbreakability", it needed to be toasted first.

I witnessed that this chap stuck the blade into the intense heat for about 30 seconds. When it was red hot, he pull it out, aired it for a while and then dipped it into the water for about 3 seconds.

He quickly pulled it out again, waved it around a little and then dipped it (just the sharp edge) into the water and then withdrew it. He did it three or four times.

Finally, he sharpened it. I told myself: "An old method of heat treatment." I wonder if those who are familiar with heat treatment consider this a sound procedure for hardening blades.

I respected the knife maker's experience concerning his way of heat treating the knife. Probably his knowledge is culled from decades of "playing with fire".

I thought maybe there are other knife makers out there who used the "ancient method" and do the same with blades.
 
That is called water quenching, and is the hardening step of heat-treatment. It sounds like this guy also does what is called edge-quenching, cooling the edge quickly, but leaving the spine hotter, longer. This will result in a softer spine compared to the edge. This is differential tempering.

Performed properly by someone who knows what he is doing, it will produce a fine blade. The makers of the American Bladesmith Society and the neotribal metalsmiths do this all the time. Using spring steel (probably 5160) and a water quench is the same way the Nepalese Kamis make khukuri blades. Nothing really new here. The old methods are still with us because they work.

You can not do this with every steel, but for simple carbon steel alloys, this technique can work. Some steels are quenched in warm oil which does not cool the steel quite as rapidly. Other steels are simply left to cool in the air. Many steels benefit from a tempering step, using relatively low heat to soften the blade somewhat.

A properly done differential quench may not require a seperate 'tempering' step. Japanese clay-tempering is performed by coating portions of the blade with clay to hold in heat in some parts of the blade, which will result in a differential temper without additional 'tempering' and has the advantage of beautifully displaying the differerent hardnesses within the blade as 'temper' lines.

Enjoy your knife!

Paracelsus
 
I have a Bowie that Al Pendray heat treated in a bucket of water. Nice differential temper lines, too!
 
Dear Para,

Thanks for the explanation on water quenching/heat treatment.

That guy knew what he was doing. He applied the heat/water treatment on the axe I bought from him.

After the water treatment, he tested the axe on a big block of wood. Came up aces!

I, for one, was convinced by his method. You are right, he was using carbon steel.
 
Just think of how many Knives and axes were heat treated in this manor during the frontier days of our great country.The way we do things now days is only due to the fact that we now have electricity that they didn't have back then....
Check out the Neo-Tribal guys forum and you will see allot of this style of forging and heat treatng being done...
It does work great and with practice you can keep everything consistant from blade to blade.
Bruce
 
Bruce, you are obviously a man who is well acquainted with fire and steel.

I am a witness to such knife makers who make knives almost from pure subconscious. They don't have to refer to any manuals because it's all in their head.

They hold up the blade, sense its timing with their mind and then cool it in the water for that nano-second which changes the structure of the steel from ordinary to extraordinary.

The process seems simple enough to the untrained eye but to the experts, there's clearly a world of difference.
 
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