See all Blog Posts What Do Pipe Schedules Mean? Category: Hints and Tips, Pipe, Video Posted: June 5, 2015 What are Pipe Schedules? (Video Update) The schedule number on pipe products relates to the thickness of the wall on the pipe: as the number increases, the thicker the wall thickness becomes. Also, while the schedule number can be the same on different sized pipes, the actual wall thickness will be different. Here are a few examples: Pipe size 1.000” Schedule 40 – The actual wall thickness is 0.133” Pipe size 2.000” Schedule 40 – The actual wall thickness is 0.154” Pipe size 1.000” Schedule 80 – The actual wall thickness is 0.179” Pipe size 2.000” Schedule 80 – The actual wall thickness is 0.218” What we can see here is that the schedule number increases the wall size, and that the wall thickness changes based on the nominal pipe size (NPS). There are several schedule numbers used on pipe, such as schedules: 5, 5S, 10, 20, 30, 40, 60, 80, 100, 120, 140, 160, STD, XS and XXS. The most common ones used are schedules 40 and 80 What does Nominal Pipe Size or NPS mean? The NPS size represents the approximate inside diameter (not outside) of the pipe; if the schedule number on a set size is changed, it does effect the inside diameter (ID) but not the outside diameter (OD). In 1927 the American Standard Association replaced the previously used Iron Pipe Sizing (IPS) with Nominal Pipe Sizing (NPS). This North American standard is used on pipes for high or low pressures and temperatures. Example: NPS OD Schedule # Wall Thickness ID 1.000” 1.315” SCH 40 0.133” 1.049” (approx.) 1.000” 1.315” SCH 80 0.179” 0.957” (approx.) All pipes are specified using the NPS and schedule numbers. It is the schedule number that determines the approximate inside diameter. Video Update Don’t have time to read the blog? Check out the video blog below to learn about pipe schedules. Metal Supermarkets Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985. At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminum, tool steel, alloy steel, brass, bronze and copper. We stock a wide range of shapes including: bars, tubes, sheets, plates and more. And we can cut metal to your exact specifications. Visit one of our 100+ locations across North America today. Share: Facebook Twitter LinkedIn E-Mail Tags: nominal pipe size, NPS, pipe, pipe schedules Related blog articles What is Steel Pickling? Differences Between Hot Dip and Electrostatic Galvanizing What is Drill Rod?