Hi, my name is Fred Carson. I'm from Carson Saw Shop in Eugene, Oregon. I've been sharpening tools for over thirty years and I'm here with expert village. Ok, this is a chain saw. A classic chainsaw and you have your chainsaw file, this is a round chain, so we're going to use a round chainsaw file. And this is pretty simple. You already got your guide of your tooth. It's already there so you just have to follow it. They do sell guides, I don't particularly like them myself. You usually go up across the tooth and if it's just slightly dull about three times per tooth. It's not high tech knowledge. It does work. Personally, I like to sharpen in the field when I'm cutting wood. But then I do like to bring my chain in and get it professionally sharpened every once in a while just to level everything out and get everything straight. Looks like we're all the way around and somewhere or another you got to flip the chain so that's it's going the other way so you're working on the other teeth going in the opposite direction. Opposite side, you do the same thing. Follow your little guide. You already have your guide in your tooth. It's already right there at a thirty degree angle. Or at a twenty-five degree. Twenty-five, thirty degree angle, preferably three times on each tooth. Then you move the chain to the next tooth. You're done with that, then you also have these little straight edge. You want to see if you want to make sure that these guides right here, they have to be lower than your tooth. Otherwise, you're not grabbing wood. So, to do that you have a flat file and you do two or three strokes on each one of these. If you do get them too low, by chance, then the chain will want to stop. It should be ten to twenty thousandths lower than your tooth. See, it's slightly lower. It's about perfect. That's what you need to do when you sharpen a chain out in the field. And they will cut, they will cut fast.