Stainless steel pipes are used in constructions, food industry, pharmaceutical industry, petrochemical industry, automotive industry, municipal and decorative purposes. Pipe comes in a variety of Schedules (SCH), which refers to the wall thickness of the pipe. Popular Schedules of pipe are SCH 40 and 80. A pipe’s O.D. will remain the same among the different pipe Schedules. It is the Schedule that will vary among the Nominal Pipe sizes.