Trimming is a term used when a part needs an edge smoothed out and the burrs removed.  Oftentimes, a part is put either on a lathe or a trim/bead machine and a cutter will start to shear or shave off the edge to run true.  A trimmed edge can be a straight off trim or the trim can be radiused or beveled to make the edge safe for handling.  An edge is oftentimes trimmed before beading or edge rolling.  The tool used to trim is called a cutter or an insert.  These tools can be designed to apply the correct trim the customer desires whether it be a straight edge, a beveled edge or a radiused edge.  A skilled metal spinner can trim an edge with a high degree of accuracy.  In some instances, parts are spun to a near net dimension and the spinner then goes and does a final trim on the part to achieve the desired dimension.  A skilled metal spinner can trim an edge to be within 1/64th of an inch – all by sight and feel.  Depending on the part configuration, the part is checked with a Vernier caliper, a micrometer, a pi taped band and even a tape measure.  Many times, tolerances are +/- 1/16”, but skilled spinners can work within +/- .005”, depending on part configuration and material used.