How did they manufacture cast metal handled knives?

L

Legendary_Jarl

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Feb 8, 2010
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Hello,

I came up with a project idea the other day. I thought of grabbing a folding knife blade and turning it i to a fixed blade knife by casting a handle around the base of the blade maybe 1 inch deep. I was originally thinking copper but then it dawned on me that even if I used something like aluminum I would be exposing an already heat treated blade to at least 1220F which would surely ruin the heat treatment of the blade? How did they do it in the case of knives like the Gerber Mark 1 & 2? Did they do the heat treatment after casting the handle or did they simply glue it in place? Any ideas?

Thank you!
 
Gerber Mark daggers had a hollow socket the blades were glued into. But those were thrusting weapons that the manual basically said shouldn't be used for anything except poking holes in people. Their working knives and kitchen knives were cast right on the blades as far as I know.
 
The Gerber Mark I and Mark II and Command series have the blades epoxied into the already cast handles. However I am not sure how the older Gerber sporting series knives like the Magnum Hunter, Flayer, Big Hunter, Pixie Coho, etc. were put together. I believe they were cast onto the blade. They could have used a heat sink or maybe they heat treated the blade after casting the handle onto the blade. Years ago I had a Cold Steel Shinobu Folder with a broken handle that I turned into a fixed blade by fitting the blade and the lockback portion of the knife into a Cocobolo handle with epoxy and then I made a blade cover / sheath out of Oak. It turned out OK. I hope whatever method you try works well for you. Please let us know how it worked.

ShinobuFixed02.jpg
 
Here's a neat video about the process used by Ruana Knives in Montana. They are famous for their cast aluminum handles. It looks like they try to keep the blade cool by dunking in water as soon as possible after the aluminum is poured into the mould.

 
As far as using a folding knife blade. I don’t think it would stand up to hard use. Aluminum is soft. (In my opinion) You would have to weld a tang on to it.
 
Since aluminum and steel have such different coefficients of thermal expansion (aluminum is about double that of steel), I'm not sure how they could pull it off and get a good bond.

Also, even in a sand mold, it seems like the steel is gonna get too hot no matter what you do, because aluminum melts at such a high temperature and because aluminum is so hugely thermally conductive, which means the molten aluminum is gonna dump heat into the knife blade faster than damp sand can pull it back out. (Only copper, gold and silver are more conductive IIRC.) I'm wondering whether they could join the aluminum handle and knife while the knife steel is in a normalized condition, then quench and temper the whole thing later...

Another possible method might be to use a "dummy" tang of mild (or normalized) steel as a male mold (or pattern), and fashion it so you could pull the blade out of the aluminum handle after the handle is cast, then epoxy the completed handle onto the already-heat-treated knife....
 
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