The Five basic Finishes for ASME B16.5 and ASME B16.47 Flanges are the Stock Finish, Spiral Serrated Finish, Concentric Serrated Finish, Smooth Finish and Cold Water Finish. The Stock Flange Finish is a continuous groove produced by using a 1/16” radius round nosed tool with a feed of 1/32” per revolution. This is the Standard Flange Finish unless otherwise specified by the purchaser. The Spiral Serrated Finished is also a continuous groove but uses a 1/16” V shaped tool at a 1/64” depth with a 1/32” feed. The Concentric Serrated Finish is made up of separate grooves using a 90* V shaped tool making the grooves 1/64” deep and 1/32” apart. The Smooth Finish can be produced using several different shaped tool’s, this finish shows no visible serrations and has a 63-125 RMS. The Cold Water Finish is made by using a wide tool at high speed, it has a mirror like appearance and this Finish is generally used without a gasket with a 32-62 RMS surface Finish. Also note the gasket face of Pipe Flanges shall be judged by visual comparison with Ra Standards and not by instruments with a Stylus Tracer or Electronic Amplification per ANSI/ASME B46.1. Contact Coastal Flange with any questions or to receive a quote tailored to your requirements.