would this be good or bad in a knife

[Patrick F]

make a billit out of high carbon steel then open up one side and put a mild steel in for the spine??
i was thinking this might be good because the outer shell of high carbon can keep an edge and the mild steel spine would bend more and what not so it wont break.
also i would do clay heat treating so the spine isnt heat treated as much as the edge.

[pkrankow]

It would be easier to fold the high carbon steel. There will be a possible future problem of wearing through the high carbon into the mild. This technique has been done before, but I do not know the name of it.

An alternative is to sandwich the high carbon between 2 pieces of mild so the high carbon is exposed as the mild is ground away. This technique has also been done before, and is called San Mai

Phil

[edge9001]

the technique you describe, wrapping the mild core with HC, was used at one time to make katana in japan. it was used because it does act exactly as you have described. the only problem is as phil said, eventualoy you will sharpen through the highcarbon steel. the 3 layered method phil mentioned would allow the blade to be sharpened till it was worn away without this issue.

but yes you design would have its place in blades.

just my 2 cents

[ThomasPowers]

Remember if you are not skilled the "fancy methods" of making blades will probably result in *worse* outcomes than the simple ones.

As for sharpening through the HC edge material---few of us ever use *1* blade so much that will happen---and then you could always do like they did for medieval knives and weld on another strip of high carbon steel for the edge. (Most of medieval knives were plain wrought iron with just a hich C edge applied---the method of applying that edge---lap weld, but weld, cleft weld, etc is one of the ways they are grouped---see "Knives and Scabbards, Museum of London" for a good write up on this and over 300 examples of medieval knives---including folding ones.)

Now you do know that if you use a true mild steel for the spine then clay hardening won't do anything as the true mild wouldn't harden anyway, right?

By your type of questions I would say you are not quite ready to "get fancy" and would best spend the time perfecting your welding and forging skills before trying the oddball methods of making blades. No slight intended I've been smithing blades for over 30 years now and pattern welding for 27 and I still would to practice a bunch before I tried say an alternating chevron blade of wootz and pattern welded material---and I've seen that done in person!

[Playinwitmetal]

Your best bet is probably to differentially harden the hc-steel. Use clay or a refractory material to coat the spine and parts of the steel you want to remain soft, then heat the blade to bright reddish orange, and then quench it in your choice of water or oils. after that temper it in an oven at 350 degrees for 2 cycles of 1 hour. the result with leave you with a hardened edge and a softer, more ductile, bendable blade.

[ThomasPowers]

Of course that method works best for shallow hardening steels. Most of the high alloy knife steels you would do better with an edge quench and/or a differential tempering.