Your saw could have 3/8 pitch lo-profile (if Oregon, then it will have 91 on the drive link) or else .325 pitch (if Oregon, then will have 33 on the drive link). You can measure the distance from a point on one tooth to the same point on the next tooth to confirm the pitch. If the distance is 3/4 inch, then it is 3/8 pitch. If the distance is closer to 5/8 inch, then it is .325 pitch. If the tooth has an inscribed line across the top, then stay parallel with that line. If the pitch is .325, then you could have either full-chisel or semi-chisel chain. Semi-chisel teeth have a beveled leading corner. For 3/8 pitch lo-profile and .325 pitch semi-chisel the horizontal angle is 30 degrees. Full-chisel teeth have a sharp corner where the top plate meets the side plate at a point. For full-chisel teeth, the horizontal angle is 25 degrees, and the vertical angle is 10 degrees,with the high end of the file at the leading corner of the tooth.
