Schedule 40 Stainless Steel Pipe Dimensions

Stainless steel pipe (SS Pipe) is widely used in industries requiring corrosion resistance, hygiene, and durability—such as chemical processing, food and beverage, pharmaceuticals, and oil and gas. Schedule 40S is the standard wall thickness series for stainless steel pipes as defined by ASME B36.19, where the “S” suffix distinguishes stainless steel schedules from carbon steel schedules (ASME B36.10).

What is a Schedule 40S  Pipe?

The schedule number indicates the wall thickness of a pipe. For a given NPS (Nominal Pipe Size), the outside diameter remains constant, while the wall thickness increases with higher schedule numbers. Schedule 40S is commonly used for general corrosive service and moderate-pressure applications.

It is important to note that for NPS 8 and smaller, Schedule 40S wall thickness matches carbon steel Schedule 40. However, for NPS 10 and above, Schedule 40S is thinner than Schedule 40—this is why the “S” suffix must be specified when ordering stainless steel pipe. For more details on pressure ratings, refer to our Schedule 40 Pipe Pressure Rating Guide.

Schedule 40S Stainless Steel Pipe Dimensions – Metric (mm) with Weight

The table below provides complete dimensional data for Schedule 40S stainless steel pipes per ASME B36.19, covering NPS 1/8 to NPS 24. It lists outside diameter (mm), wall thickness (mm), and weight per meter (kg/m) for each size, offering a convenient reference for projects using metric units.

Schedule 40S Stainless Steel Pipe Dimensions – Imperial (inches) with Weight

The table below provides complete imperial dimensions for Schedule 40S stainless steel pipes per ASME B36.19, covering NPS 1/8 to NPS 24. It lists outside diameter (in), wall thickness (in), and weight per foot (lb/ft) for each size, offering a convenient reference for projects using imperial units.

Common Applications of Schedule 40S Stainless Steel Pipes:

Schedule 40S stainless steel pipes are commonly used in:

● Chemical and petrochemical processing – corrosion-resistant fluid transmission
● Food and beverage industry – sanitary piping systems
● Pharmaceutical manufacturing – clean, non-contaminating process lines
● Water and wastewater treatment –Corrosion-resistant piping systems

Material Grades:

Schedule 40S stainless steel pipes are available in common grades such as 304/304L and 316/316L, and are typically manufactured to ASTM A312 for SS seamless and welded pipe, with finishes including annealed and pickled.

Standards Reference:

ASME B36.19 – Stainless steel pipe dimensions and wall thickness
ASTM A312 – Standard specification for seamless and welded stainless steel pipe

△Key Distinction: ASME B36.19 (stainless steel) and ASME B36.10 (carbon steel) have different wall thicknesses for NPS 10 and above. Always specify the correct standard when ordering.

Frequently Asked Questions (FAQ):

1. What is the difference between Schedule 40 and Schedule 40S?
Schedule 40S is specifically for stainless steel pipes under ASME B36.19, while Schedule 40 applies to carbon steel under ASME B36.10. For NPS 8 and smaller, the wall thicknesses are the same; for NPS 10 and above, Schedule 40S is thinner.

2. What material grades are available for Schedule 40S stainless steel pipes?
Common grades include TP304/304L and TP316/316L (ASTM A312). These materials provide excellent corrosion resistance for a wide range of industrial applications.

3. How to calculate the weight of Schedule 40S stainless steel pipe?
The weight per meter can be calculated using the formula: Weight (kg/m) = (OD – WT) × WT × 0.02466, where OD is the outside diameter and WT is the wall thickness (both in mm). The table above provides standard values for reference.

Related resources:

● SCH 40 vs SCH 40S Pipe Selection Guide – Carbon Steel vs Stainless Steel

● How to Calculate the Pressure of SCH 40 Stainless Steel Pipe?

● Complete Size Chart of Stainless Steel Pipes

For precise pipe sizes and custom specifications, contact our technical sales team: sales@hu-steel.com