If you are roughing, choose a 36 to 80 grit.
If you are intermediate grinding, use 80 through 180 grit.
If you are finishing, use 220 through 240 grit.
What is a mesh vs. Grit size?
If you take a (1) inch space and add wires to it, the number of openings within the 1″ space is defined as mesh. For example, if the 1″ space has ten openings for particles to fall through,