A Different Way to Quench

David Stifle

David Stifle

Joined
Nov 20, 2008
Messages
10,188
Hi Guys,

I've been hanging out over in the Himalayean Imports forum for the past couple of days, and one of the members there was kind enough to send me a link showing how the Kami's (makers) make kukri's. Fascinating stuff! They start in the shop as little kids, and are not awarded the title of Master until they are in their forties. And I thought the ABS was tough:)

But, to my question at hand. When they quench, they do not put the blade in water, but rather pour water on the blade. I've handled kukri's, and they do have a hard quenched edge. But, what's going on here? How does this technique work? I can not quite get my mind around this process.

Dave
 
I think it would depend on the steel and using what they have available as a quenchant. Likely the steel is recycled truck springs also likely 5160 which is deep hardening. A full quench into a bucket of water would be too severe but pouring water on it reduces the severity and thus no cracking but still cools fast enough for the 5160 to harden.

That's my guess anyway.
 
They like scrap steel especially Mercedes Benz springs which are 5160Mod. But you don't have to dunk it in the quenchant. Industrially especially with quenching sheet or plate they sometimes use a spray system.The plate is passed through a line of high pressure nozzles spraying the quenchant .This is very efficient for quenching large plates.The spray prevents vapor barriers from forming also.
Pouring water on the blade is a DIY form of spray quenching.
 
Would this method (pouring water on a blade) produce a better knive made of 5160/verus submerging the edge of the blade in the quenchant? I've been doing an interupted edge quench in a tub of water forever. Never tried just pouring water on the hot blade. How would this method affect warping? More warping, or less?

Mete, I didn't know how industry quenches large pieces of steel, very interesting.

Thanks,

Dave
 
Kukris are extreme cleavers, they do not require a extremely fine, wear resistant edge, think of the edge of an axe as opposed to a scalpel. To serve their function beautifully the same demands of hardness for other knives are not required. For thousands of years swords have done quite well ranging from 32HRC to 55HRC, but I wouldn't want that on a knife. The cutting abilities come from the blade and edge design. Also consider how many people here in the States rant and rave about blades quenched into things that can barely have a cooling curve at all, a guy in Nepal who just needs to whack through some cloth covered flesh would be more than satisfied. Consider how soft machetes are and they cut things a lot tougher than the original target of kukris.

This is not to discount what mete said, industry does overcome many obstacles by using a spray, but it is a vigorous spray over the entire surface much more capable of heat extraction than a dribbling stream. In fact the test used to classify steel as shallow or deep hardening uses a water spray from below. I would compare the cooling of the two more like a huge 120 psi blast of air against hot steel versus you blowing on it while moving from end to the other. But lets be clear, the only reason I am raining so much on this parade is because I know how information on internet forums work. If I were to simply share an interesting story about how the legendary smiths of the Koruku tribe quenched daggers by slicing papayas, by next week there could be several threads about the best place for the beginner to buy quenching papayas;).
 
I've done the KuKri pour quench with 5160, on small knives, at blacksmith demo's.

I find even rapidly flipping the blade over, you get hard and harder spots ina blade.
The first side quenched is always the hardest.
But it's a good trick for a field demo knife. :D
 
That is just ridiculous... stick with the tried and true methods.... Like quenching in dead bodies... or live ones (for a slower quench with all that body heat).:thumbup:





Rick:p
 
did we ever get the definitive answer on the turkey quench?

paging stephen fowler!!!

jake
 
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