Stainless steel SCH 40S Pipe chart

What is SCH40S?

Stainless steel pipe is a widely used pipe material in industries such as manufacturing, construction, chemical, and pharmaceuticals. It is highly favored due to its advantages such as corrosion resistance, high temperature resistance, and high strength. Sch40S is a specification of stainless steel pipe, so what is its wall thickness?

For stainless steel pipe, SCH40S defines a corresponding standard wall thickness for each nominal pipe diameter (NPS) according to international standards such as ASME B36.19 and ASTM A312. This standard is widely used in industries such as chemical, food and beverage, pharmaceutical, oil and gas, and general water or gas pipeline systems.

Standard Sizes – Stainless Steel SCH 40S Pipe Chart

The table below summarizes commonly used Nominal Pipe Sizes (NPS), outer diameters, wall thickness, and weight for SCH 40S stainless steel pipes.

Note: Some manufacturers may offer slightly different wall thickness for small-diameter pipes due to lighter applications or specific industry requirements. Always confirm the exact SCH 40S standard with your supplier.

Wall thickness series expressed by pipe weight

The American MSS and ANSI standards classify pipe wall thickness into three types based on pipe weight:
(1) Standard weight pipes are represented by STD;
(2) Thickened pipes are represented by XS;
(3) Extra thick pipes are represented by XXS.
For pipes with a DN of 250mm, Sch40 is equivalent to STD pipe.
For pipes with a DN of 200mm, Sch80 is equivalent to XS pipe.

For those interested in learning more about pipe wall thickness and pressure ratings, you can also check our article: [Schedule 40 Pipe Pressure Rating Chart and Guide], which offers detailed charts and guidance for engineers and procurement professionals.

Schedule 40 Pipe Pressure Rating Chart and Guide

Understanding pressure ratings is critical when selecting SCH 40S pipes. The pressure rating depends on pipe size, wall thickness, material grade, and operating temperature. Generally, Schedule 40S stainless steel pipes can handle medium-pressure applications, making them suitable for water, gas, and chemical systems.

Steel Pipe Wall Thickness Series The classification of steel pipe wall thickness varies across different standards. However, there are three main methods:
Representing wall thickness series by pipe schedule number (Sch.)
This is specified in the 1938 American National Standards Institute (ANSI) standard ANSI B36.10 (Welded and Seamless Steel Pipes).
The pipe schedule number (Sch.) is the ratio of the design pressure to the allowable stress of the material at the design temperature multiplied by 1000 and rounded. That is:
Sch. = P / [θ]t × 1000 (1-2-1)
Where P—design pressure, MPa;
[θ]t—allowable stress of the material at the design temperature, MPa.