Reply by MrRon

I used to have a saw sharpening service out of my home. Carbide tip blades are easy to sharpen, but you have to have the right machine to do it properly. Doing it by hand with a Dremel doesn’t work. You have to use a machine that can repeatably index each tooth accurately and do face, side and top grinds. Such machines cost over $1000. You are better off sending the blades out to a professional sharpening service. I only do my own blades now.
P.S. If you are cutting through nails, the chances are good that some teeth have gotten chipped beyond sharpening and have to be replaced and that is a whole different ball game.