Grinding Question

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unky_gumbi

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Aug 28, 2009
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I bought some 3/32" 154CM with the intention of making a pair of chef knives. I have since decided that I would like to make a couple more EDC blades and only one chef knife.

My question is at what point is the stock too thin to grind the bevels before HT?
 
Depends on your experience and how you're going to quench it. (air, plates, oil etc.)

I've ground 1/8" stock into tapered tangs down to <1/16" and edges right down to .015"; they came back from Peters' straight as can be. I kept them as straight and even as I could beforehand, I'm sure that helps.

On the other hand, if you just profile/drill them and HT before beveling, that stock is thin enough that it shouldn't take long to grind after HT. Lots of guys do that for folder blades, kitchen knives, filet knives etc.
 
I've been told the thickness of a dime is where you want to stop before heat treating to be on the safe side.
 
I will be sending the blades to knifemaker.ca for HT. I do know about the dime thickness before HT, but I have read here about post HT grinding and didn't want to screw up the steel.
 
In CPM154, you can take the blade to nearly finished. 400-600 finish and a .010 edge will be fine.

The blade thickness is not really an issue, but below .060 it is just as easy to grind after HT.
 
I think you'll find that 3/32 is on the thicker side for chef knives, although I think that's what Butch prefers. The thinner blades will likely have longer bevels at lower angles. But, wow, do they cut nicely! When I made my santoku for the KITH, the toughest part was keeping a flat bevel on a 2½" wide blade that's only 1/16" thick. I ended up losing almost ½" from the starting 3" stock. Kept grinding off the edge! Dime thickness was about 1" from the spine.

Hey, post #1234! Congrats to Frank Niro on his 1000th.
 
Ask Rob what he recommends for that style, size and steel. He knows his stuff.

unky_gumbi said:
... I have read here about post HT grinding and didn't want to screw up the steel.
Click to expand...

Basically, just keep it cool. You mentioned working on 2 or 3 blades at a time anyway; make a couple passes on one, set it in the slack bucket to cool while you make a few passes on the next one, and just keep rotating through them like that. They should never get hot enough to affect the temper that way. I do this even pre-HT just to keep my fingertips intact ;)

When you get anywhere near finished dimensions, use fine belts with a light touch so you don't put deep scratches in it.

I really think it's up to whatever you're comfortable with. I like to do as much as possible pre-HT, some guys do all their grinding after HT, most are somewhere in the middle. It can be done very nicely either way.
 
Never had any problems with 3/32 for kitchen knives, it's all about the grind. A santoku or chef's knife will work just fine out of it, sometimes chef's knives can go even thicker. The only thing I'd be leery about with 3/32 is a paring knife. I don't know any makers who use thinner stuff regularly for kitchen cutlery.

I agree that you can take it pretty much to final before heat treating.
 
Well being these will be the first knives off the new grinder I think I would be more comfortable doing most of the stock removal before HT. I did however send Rob an email to see what he would rather HT. Until then I can still finalize my designs and get them cut out and profiled. If he is fine with treating them after beveling then that is how I will go.

Thanks for all the input
George
 
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