Flat grind question

[Garrett Schmidt]

I'm kinda new to knifemaking and I just got done flat grinding my first blade. Its a pretty decent size bowie in 5160. My question is when you get done flat grinding, should you have a sharp edge or should there be a little bit of the profile edge still left before heat treat? And if so, should it be uniform along the length of the blade? I got to where it looked like the blade was even on both sides and the plunge cuts seem to be uniform but near the plunges there is more profile edge left where close to the curve near the tip it is almost at cutting edge thinkness. I guess I could just file the thinner area but that result in different over all profile, even though the change would be very small. What do you all think?

 

[richard j]

you want a flat, not a sharp edge. i leave at least a 1/32 flat on my knives before the heat treat. a sharp edge could possibly cause a crack.

 

[A C Richards]

Kill the sharp edge. It will give you headaches in the HT. Not to mention it is dangerous to work with. The profile will not be changed that much.

 

[silver_pilate]

You'd be surprised at how little the profile will change. Doesn't take much to file down that sharp edge. I've had to do it a few times, and didn't notice much change at all.

--nathan

 

[Possum]

Howdy There...!
Done a few flat grinds and I tend to agree with the idea of taking the sharp edge away before heat treat. I try to grind my blades to about half of the material thickness before heat treat and then bring down the taper after heat treat. If you do have a problem you can reprofile the blade some to get the edge correct. Have even hand sanded to get the edge and finish the way I want after heat treat. Do you scibe guide lines on the ceterline of your blades before grinding, that seems to help alot during my pre-heat treat grind. Hope this helps..!

Later "Possum":thumbup: