Quote Originally Posted by Guarnera View Post
Overheating an edge for any reason will not result in local hardening.
Over heating an edge will soften the temper. Overheating an edge to blue will probably soften the edge just a little to a spring temper. This will result in a blade that may not hold an edge as long, but will be a tougher blade and not chip out as easily. This may be what they wanted.
What were they using to sharpen that they got their blades that hot while sharpening.
In this case the machete steel was junk by our standards
and the temper nothing like an open razor.. I think they
used a dry grinding wheel with sparks a-flying but I was not
there.... I got the feeling that it was a local air quenched
edge that lasted a day that they liked.