Choosing the Right File

1. Select a coarseness rating. From smoothest to roughest, the ratings are:- dead smooth, smooth, second cut, bastard, and coarse.
2. Measure the file from heel to point. The heel is where the file begins to taper into the tang - the part the handle goes on. The longer the file, the further apart the teeth are; therefore, longer files are coarser than shorter ones.
3. Go by the rule: Large, coarse files are for rough shaping and trimming materials; fine, small files are for sharpening and smoothing edges.
4. Match the file's shape to the work. Files are shaped to be round, half-round, square, flat or triangular. If you are filing a V-shaped work piece, for example, you would want to use a triangle-shaped file. On the other hand, if the work area requires a gentle curve, a half-round file is ideal. Square files work well for inside 90 degree corners, and round files are made for smoothing round holes. Flat files are good all-purpose files for any flat, straight edge.
5. Use a single-cut file when shaping or smoothing ferrous metals.
6. Look for a double-cut file for projects that need material removed and don't require a smooth finish.
7. Consider a file with curved teeth for removing material with a smooth finish. Brass, aluminum and other nonferrous materials are best for this type of file.