Well 1 mm for a nick is actually pretty deep. I have some razors with some really tiny nicks in them probably less than .25mm and they shave great. It also depends where the nick is. If its towards either ends it will probably be less noticeable than if its towards the middle. Of course once you start honing it out then you need to hone down the entire edge until its all equal. Thats why I say if it shaves ok leave it alone unless your one of those real anal guys that demands pefection.