Ray Rogers Handcrafted Knives

The Nitrogen Dewar

This is a nitrogen dewar for liquid nitrogen. Basically, they are oversized thermos bottles designed to hold super cold (minus 300 degrees) liquid nitrogen. Part of the heat treating process is the cryogenic quench. That's where these guys get used - just put your blades in there, very carefully and slowly.

You do it carefully because even a room temperature piece of steel causes the super cold liquid to boil. If you drop the blade in the tank and splash yourself it's possible to be seriously injured. Also, there's the problem of not getting that blade back anytime soon.

You do it slowly because lowering the warm steel into the tank too fast can cause the blade to crack. I'm sure you've seen the classic experiment where a fresh rose is lowered into super cold liquid and then withdrawn and shattered against a table. Think about it before you get careless with this stuff.

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Ray Rogers Handcrafted Knives