Japanese saw blade for knife blank?

I looked for the answer, but google was not much help.

I just replaced the blade in my japanese saw and want to use the old blade for making a few kitchen knives (nothing fancy, just want to give it a try). I'm really impressed with these saw blades and I think they would make fine knives. The blade is a 250mm Bakuma from Woodcraft ($8.50). The metal is too hard for a file to cut and the little dremel cut-off wheels disappear quickly. The website says that the steel is "impulse hardened" to RC63. The blade is about .020 thick so it is about right for a paring knife or maybe a steak knife, it is flexible enough to make a nice fillet knife.

I would like to cut the knife blade profile without annealing the steel (to preserve the current temper). I'm not sure how to do this - the cut-off wheels are slow and I'm not very accurate cutting with them, plus it would "eat a lot of wheels". If I anneal the steel, I'm not sure I can properly harden and temper the knife blades.

Anyone have some guidance?

Thanks

Bruce

Reply to
Bruce C.
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What I do with my collection of Sandvik HSS power hacksaw blades is to cut the shape out with the silicon-carbide cutoff wheels on a Dremel, or with larger wheels of the same type on my old B&D die grinder.

Either way, it's a very slow go. But, when you're dealing with heat treatments that you don't want to or can't replicate, it's the only way I can think of to do it in my home shop. If I had a wirecut EDM machine, life would be a lot easier.

I don't think I'd take the time to do it for a paring knife. I have done it for a left-and-right pair of Murphy knives (straight cuts; very simple) and for a skinning knife (all curves, not so simple). The latter took me about half a day, between cutting it out and grinding it SLOWLY into shape.

If you have time in your life to do things like whittling chains and balls-in-cages, it's no big deal. If you have a real life, it may not be worth it.

-- Ed Huntress (remove "3" from email address for email reply)

Reply to
Ed Huntress

No thanks. I have enough junk in my basement already.

Ed Huntress

Reply to
Ed Huntress

The saw blade is too hard. Tin snips don't even leave a mark. I tried a file to test the hardness and it burnished the teeth on the file. This is why I think the steel is too good to just pitch into the dumpster and I think it would hold a nice knife edge. Another thing, I like the flexability of the blade - this is the part that supprised me. I was expecting anything that hard would be very brittle.

After thinking about it some more, I'm going to cut off a test chunk and experiment with annealing and rehardening. If I'm successful with that, it sure would make the knife making go quicker.

I don't especially need another paring knife but the steel is only about .020" thick. Probably the best use for it would be a filet knife considering the flexability.

Bruce

Reply to
Bruce C.

Follow-up:

I cut a small chunk off the saw for a test piece. I was able to anneal the steel with no problem. I could file it and cut it with my jewelers saw. So now I hardened it - quenched in ice water (I figured if it was going to shatter on the quench, I wanted it to happen with the test piece). Still working great, the metal is brittle enough to snap with my fingers and the file wont touch this stuff. Time to temper (and here is where the problem starts), I polished one side with emory cloth and put it in the toaster oven on a scrap of aluminum foil. After about 12 min, I see colors dancing on the steel. When I pulled it out it was mostly blue (almost a neon purple) and some dark straw colors scattered around. Well the temper must have not gone very deep or been incomplete because I could still snap the steel with my fingers.

It looks like I could use some guidance with the tempering - anybody have any ideas?

Bruce

Reply to
Bruce C.

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