Been reading a lot on filing tech. and have learned a lot and have a lot to learn. Did not realize how criticle it was. One simple ? I could not find the answer to. Which way should you stroke the file? When sharpening a knife I stroke into the edge and have been doing the same on chains. However, when I read that it was best to angle the file down 10 deg. did not make sense when that would go against the angle of the cutter.