Differences Between a Schedule 10 & a Schedule 40 Pipe

By Harvey Sells

Updated January 09, 2018

The pipes used in recent years are based more upon pressure than wall thickness.
i Screw image by Adwenture from Fotolia.com

Schedule 10 and Schedule 80 refer to the difference in wall thickness. The American Society for Testing and Materials established the standards. While the ASTM has evolved into an international organization, the standards are still widely used for pipes in the U.S.

Operating Pressure

In the past, pipes were chosen based upon wall thickness. Decades ago, Schedule 40 would have been used where Schedule 20 and even Schedule 10 are currently being used. The selection of the thinner wall pipes are based upon the pressure at which they will operate. While initial cost and weight can be reduced by using the thinner pipes, there is little room for corrosion which can lead to pipe failure.

Schedule 10 and Schedule 80 Wall Thickness

Wall thickness will increase with the increase of pipe diameter. Pipe of 1/8-inch nominal diameter has a wall thickness of 0.049 inches for Schedule 10 and a wall thickness of 0.068 inches for Schedule 80. The scale for Schedule 10 and Schedule 80 pipe goes up to a nominal size of 36 inches. At 36 inches, Schedule 10 has a wall thickness of 0.312 inches while Schedule 80 has a wall thickness of 0.500 inches.

Schedule 10 and Schedule 80 Weight

The weight for 1/8-inch nominal diameter Schedule 10 pipe is 0.1863 per foot while Schedule 80 weighs 0.3145 pounds per foot. Values will vary from carbon steel to stainless and plastic pipes.