Cutting edge after heat treat

H

Hunterarrow

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Do you grind off the cutting edge of the knife after heat treat?
I'm asking this because I've always put the edges on after heat treat, not worrying about taking back the edge to remove the surface metal that may have been weakened by the heat treat process. I mean the very cutting edge of the knife is very close the the surface metal when the blade was heat treated. Is this a problem? I'm sending two chisel grind knives to heat treat this week. Should I remove the surface metal on the flat side after the heat teat to get to the 'good' steel?
 
I place a secondary grind on all my blades when sharpening. There is no need to worry that the metal here will be defective. Frank
 
I'm not quite sure if you're asking about decarb problems or asking if the edge was left too thin/thick when you sent them out for treatment...

Generally, the surface of the steel will experience some decarb, though unless the heat treatment or forging was seriously overdone the decarb should only be microns thick - no thicker than the scale on the surface, with "good" steel underneath. However, if you grind the edge down AFTER heat treatment, light and slow does it - you don't want the edge to get too hot at this point. If it's edge thickness you are concerned about, most makers seem to follow the guideline of "penny thickness" before heat treatment. While there's a good reason for leaving that much material on the edge, I can say that not once have I had a single problem when taking mine down to the thickness of copy paper.

I *think* this answers your question. If I misunderstood then sorry, please disregard my post.
 
Decarb is time and temperature dependant.If grinding after HT there should not be a decarb problem. However grindind after HT can be and there are many examples of that !!
Keep cool when grinding during and after HT.
 
What confused me a bit is that I've seen that most manufacturers will HT the blade blanks and then do all the grinding after that (machining is a bit variable from manufacturer to manufacturer)... The only exception I saw was BM- and they do the 'major' grinding work prior to HT only for very few steels (M4 oand one or two others), because so much grinding after HT would be too difficult.
 
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