Tools lose their edge and become dull. That’s a fact of their existence. But it’s also a fact that they need not stay that way. Sharpening nearly anything, from a shovel to a putty knife to a plane to ...

I've been thinking about buying one of these but I don't know if they are just a gimmick. Also, if they genuinely work well how good do your bits need to be in the first place to be worth sharpening?