Finishing countersink washers are meant to be used with countersunk screws to keep them from sinking into surface of a softer fastening material, as well as increasing the bearing surface so that the load is distributed over a larger area. Screw heads must be sized to fit into the recessed center of the washer. Nickel plated steel.

Note: I.D. stands for inside diameter. O.D. stands for outside diameter.