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Stainless Steel Pipe Size Chart
Stainless Steel Pipe Size Chart: Dimensions, Schedules, Weight & Selection Guide
A Stainless Steel Pipe Size Chart lists the key dimensions of stainless steel pipes, including outside diameter (OD), inside diameter (ID), wall thickness, nominal pipe size (NPS) and pipe schedule, in both metric (mm) and imperial (inch) units. Engineers, contractors, fabricators and procurement professionals rely on these charts to select the correct SS pipe dimensions for pressure, flow and material grade requirements, including SS 304 and SS 316.
Choosing the wrong pipe size can lead to pressure failures, flow restrictions, installation issues and unnecessary project costs. Whether you're sourcing pipes for food processing, oil and gas, pharmaceuticals, water treatment, or construction, an accurate stainless steel pipe size chart is essential for ensuring safety, performance and compliance with ASME B36.19M standards.
In this guide, you'll find a complete stainless steel pipe dimensions chart, stainless steel pipe schedule chart, stainless steel pipe size chart in mm, guidance on reading OD, ID and wall thickness, comparisons between SS 304 and SS 316 pipe sizes and practical tips to help you choose the right stainless steel pipe for your application.
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What Is a Stainless Steel Pipe Size Chart?
A Stainless Steel Pipe Size Chart is a standardized reference table that displays the dimensions of stainless steel pipes based on Nominal Pipe Size (NPS) and Pipe Schedule (SCH). It helps engineers, contractors, fabricators, and procurement professionals select the correct pipe dimensions according to pressure rating, flow requirements, and application needs.
This SS Pipe Size Chart are widely used in industries such as oil & gas, petrochemical, chemical processing, power generation, food processing, pharmaceutical, marine, construction, and water treatment. Since the dimensions are standardized, pipes, fittings, valves, and flanges from different manufacturers remain compatible.
Nominal Pipe Size (NPS)
Nominal Pipe Size (NPS) is the standardized sizing system used to identify stainless steel pipes. It represents the nominal pipe designation rather than the actual measured diameter and is used worldwide for selecting compatible piping components.
Outside Diameter (OD)
Outside Diameter (OD) is the external diameter of the pipe. For a specific NPS, the OD remains constant regardless of the pipe schedule, ensuring compatibility with standard fittings and flanges.
Inside Diameter (ID)
Inside Diameter (ID) is the internal opening of the pipe that determines flow capacity. It varies according to the wall thickness and selected pipe schedule.
Wall Thickness
Wall Thickness is the distance between the outer and inner surfaces of the pipe. Thicker walls provide greater mechanical strength, higher pressure ratings, and improved durability.
Pipe Schedule (SCH)
Pipe Schedule (SCH) is the standard classification for pipe wall thickness. Common schedules include 5S, 10S, 40S, and 80S, with higher schedule numbers providing increased pressure resistance.
Pipe Weight
Stainless steel pipe size charts often include the approximate Weight per meter or foot, helping engineers estimate transportation loads, structural support requirements, and material quantities.
International Standards
Standard Stainless Steel Pipe Size Charts are manufactured according to ASME B36.19M for stainless steel pipes and ASME B36.10M for carbon and alloy steel pipes. These standards ensure consistent dimensions across manufacturers, making pipes, fittings, flanges, and valves fully interchangeable.
Stainless Steel Pipe Size Chart in MM and Inches
The table below provides the standard Stainless Steel Pipe Size Chart showing Nominal Pipe Size (NPS), Outside Diameter (OD), and wall thickness for the most commonly used Schedule 10S, Schedule 40S, and Schedule 80S pipes. All dimensions are based on ASME B36.19M, the internationally recognized standard for stainless steel pipe dimensions.
| NPS | OD (mm) | SCH 10S (mm) | SCH 40S (mm) | SCH 80S (mm) |
|---|---|---|---|---|
| 1/8" | 10.3 | 1.24 | 1.73 | 2.41 |
| 1/4" | 13.7 | 1.65 | 2.24 | 3.02 |
| 3/8" | 17.1 | 1.65 | 2.31 | 3.20 |
| 1/2" | 21.3 | 2.11 | 2.77 | 3.73 |
| 3/4" | 26.7 | 2.11 | 2.87 | 3.91 |
| 1" | 33.4 | 2.77 | 3.38 | 4.55 |
| 1-1/4" | 42.2 | 2.77 | 3.56 | 4.85 |
| 1-1/2" | 48.3 | 2.77 | 3.68 | 5.08 |
| 2" | 60.3 | 2.77 | 3.91 | 5.54 |
| 2-1/2" | 73.0 | 3.05 | 5.16 | 7.01 |
| 3" | 88.9 | 3.05 | 5.49 | 7.62 |
| 4" | 114.3 | 3.05 | 6.02 | 8.56 |
| 5" | 141.3 | 3.40 | 6.55 | 9.53 |
| 6" | 168.3 | 3.40 | 7.11 | 10.97 |
| 8" | 219.1 | 3.76 | 8.18 | 12.70 |
| 10" | 273.0 | 4.19 | 9.27 | 15.09 |
| 12" | 323.9 | 4.57 | 9.53 | 17.48 |
Stainless Steel Pipe Dimensions
Understanding Stainless Steel Pipe Dimensions is essential for selecting the correct pipe for your application. Every Stainless Steel Pipe Size Chart includes key dimensional parameters that determine the pipe's compatibility, pressure rating, flow capacity, and overall performance.
Outside Diameter (OD)
The Outside Diameter (OD) is the external diameter of the pipe. For a specific Nominal Pipe Size (NPS), the OD remains constant regardless of the pipe schedule.
Example: 2" Pipe = 60.3 mm OD
Inside Diameter (ID)
The Inside Diameter (ID) is the internal opening of the pipe and determines its flow capacity. It varies according to the wall thickness of the selected schedule.
Formula: ID = OD − (2 × Wall Thickness)
Wall Thickness
Wall Thickness directly affects the pipe's pressure rating, mechanical strength, and service life. Standard schedules include 5S, 10S, 40S, 80S, 160, and XXS.
Nominal Pipe Size (NPS)
Nominal Pipe Size (NPS) is the standardized pipe size designation used throughout the piping industry. It is a nominal value and does not represent the actual measured diameter.
Example: A 2-inch NPS pipe has an actual Outside Diameter (OD) of 60.3 mm.
Pipe Schedule
The Pipe Schedule (SCH) specifies the wall thickness of the pipe. Higher schedule numbers indicate thicker walls, greater pressure resistance, and improved mechanical strength. Common schedules for stainless steel pipes include SCH 5S, SCH 10S, SCH 40S, SCH 80S, SCH 160, and XXS.
Stainless Steel Pipe Schedule Chart
A Pipe Schedule (SCH) indicates the wall thickness of a stainless steel pipe. As the schedule number increases, the pipe wall becomes thicker, enabling it to withstand higher pressure, elevated temperatures, and demanding industrial applications.
| Pipe Schedule | Typical Applications |
|---|---|
| Schedule 5S | Low-pressure systems and light-duty piping. |
| Schedule 10S | Food processing, pharmaceutical, water supply, and sanitary piping systems. |
| Schedule 40S | General industrial process piping, manufacturing plants, and utility services. |
| Schedule 80S | High-pressure, heavy-duty, chemical processing, and oil & gas applications. |
| Schedule 160 | Severe service environments requiring high pressure resistance. |
| XXS | Extreme pressure and critical industrial applications. |
The Pipe Schedule System was developed to standardize wall thickness across different pipe sizes. In general, a higher schedule number indicates a thicker wall, greater pressure resistance, a smaller inside diameter (ID), and increased mechanical strength.
Benefits of Higher Pipe Schedules
- Thicker wall thickness for improved durability.
- Higher pressure and temperature resistance.
- Smaller inside diameter (ID) due to increased wall thickness.
- Greater mechanical strength and overall pipe weight.
Common Stainless Steel Pipe Schedule Designations
Schedule 5S & 10S
Thin-wall stainless steel pipes commonly used in low-pressure applications such as water supply, HVAC systems, food processing, pharmaceutical plants, and sanitary process piping. Schedule 10S stainless steel pipes are widely preferred where corrosion resistance and cleanliness are essential.
Schedule 40S
The most commonly used stainless steel pipe schedule for general industrial applications. Schedule 40S offers an excellent balance of pressure capacity, mechanical strength, and cost-effectiveness.
Schedule 80S
Heavy-wall stainless steel pipes designed for high-pressure and high-temperature service, including chemical processing, steam lines, power generation, refineries, and oil & gas industries.
Schedule 160 & XXS
Extra-heavy wall pipes intended for extreme pressure and severe operating conditions where maximum strength, durability, and long-term reliability are required.
SS 304 vs. SS 316 Pipe Size Chart: Which Grade Should You Choose?
Stainless Steel 304 and Stainless Steel 316 are the two most commonly used stainless steel pipe grades. Both are manufactured in the same Nominal Pipe Sizes (NPS) and pipe schedules, but they differ in chemical composition, corrosion resistance, and ideal service conditions.
| Property | SS 304 | SS 316 |
|---|---|---|
| Chromium | 18–20% | 16–18% |
| Nickel | 8–10.5% | 10–14% |
| Molybdenum | None | 2–3% |
| Corrosion Resistance | Excellent | Superior |
| Chloride Resistance | Good | Excellent |
| Available Sizes | 1/8" to 24" | 1/8" to 24" |
| Available Schedules | 5S to XXS | 5S to XXS |
| Common Standards | ASTM A312 TP304 / TP304L | ASTM A312 TP316 / TP316L |
| Typical Applications | Food Processing, Water Treatment, Architecture | Marine, Chemical Processing, Pharmaceutical & Offshore |
Choose SS 304
SS 304 is the preferred choice for general-purpose industrial applications where excellent corrosion resistance, durability, and cost-effectiveness are the primary requirements.
Choose SS 316
SS 316 is recommended for marine, coastal, pharmaceutical, and chemical processing environments where superior resistance to chlorides, pitting, and crevice corrosion is essential.
Seamless vs. Welded Stainless Steel Pipes: Does It Affect Dimensions?
The manufacturing method—Seamless or Welded—does not change the standard dimensions listed in a Stainless Steel Pipe Size Chart. Both types are produced according to ASME B36.19M standards using the same Nominal Pipe Size (NPS), Outside Diameter (OD), Inside Diameter (ID), and wall thickness.
The primary differences are found in their manufacturing process, pressure handling capability, mechanical strength, and recommended applications.
| Feature | Seamless Pipes | Welded Pipes |
|---|---|---|
| Manufacturing | Extruded from a solid billet | Manufactured by forming and welding stainless steel strip |
| Pressure Rating | Higher | Moderate |
| Strength | Excellent | Good |
| Cost | Higher | More Economical |
| Common Applications | Oil & Gas, Power Plants, High-Pressure Systems | Water Supply, Food Processing, Construction & General Industrial Piping |
For high-pressure and critical services, seamless stainless steel pipes are generally preferred. For general industrial, commercial, and structural applications, welded stainless steel pipes provide an economical and reliable solution.
How to Read Stainless Steel Pipe Dimensions
When using a Stainless Steel Pipe Dimensions Chart, follow these simple steps to identify the correct pipe size for your application.
- Identify the required Nominal Pipe Size (NPS).
- Check the corresponding Outside Diameter (OD).
- Select the required Pipe Schedule (SCH).
- Note the specified Wall Thickness.
- Calculate the Inside Diameter (ID) if required.
- Verify pressure rating and operating conditions.
- Select the appropriate stainless steel grade such as SS 304 or SS 316.
How to Choose the Right Stainless Steel Pipe Size
Selecting the correct stainless steel pipe size ensures optimum system performance, safety, and long-term reliability. Consider the following factors before choosing a pipe.
- Operating pressure requirements.
- Required flow rate and fluid velocity.
- Operating temperature.
- Corrosion resistance requirements.
- Material grade (SS 304, SS 304L, SS 316, SS 316L, etc.).
- Pipe Schedule (SCH 5S, 10S, 40S, 80S, etc.).
- Applicable ASTM and ASME standards.
- Budget, installation method, and project specifications.
Frequently Asked Questions About Stainless Steel Pipe Sizes
A stainless steel pipe size chart is used to identify the exact Outside Diameter (OD), Inside Diameter (ID), wall thickness, and pipe dimensions based on the Nominal Pipe Size (NPS) and pipe schedule. Engineers, fabricators, contractors, and buyers use these charts to select the correct pipe for pressure, flow, and application requirements.
The Outside Diameter (OD) is the external diameter of the pipe, while the Inside Diameter (ID) is the internal opening through which fluid flows. For a given NPS, the OD remains constant, whereas the ID decreases as the wall thickness or pipe schedule increases.
Pipes are specified by Nominal Pipe Size (NPS) and pipe schedule, primarily for transporting liquids and gases. Tubes are specified by their actual outside diameter and wall thickness and are generally used in structural, mechanical, and precision engineering applications.
First identify the required Nominal Pipe Size (NPS), then select the appropriate pipe schedule (such as SCH 10S, SCH 40S, or SCH 80S). The chart will provide the corresponding Outside Diameter (OD), wall thickness, and Inside Diameter (ID) for your application.
Schedule 40S is the most commonly used stainless steel pipe schedule for general industrial applications. Schedule 10S is widely used in sanitary and food processing systems, while Schedule 80S is preferred for higher-pressure applications.
Yes. SS 304 and SS 316 pipes follow the same dimensional requirements specified in ASME B36.19M. The pipe sizes, outside diameter, wall thickness, and schedules are identical; only the material composition and corrosion resistance differ.
Stainless steel pipe size charts in millimeters are available from trusted manufacturers and suppliers such as Kamal Steels. They are also included in the ASME B36.19M standard and are commonly provided on product pages or downloadable technical data sheets.
A Stainless Steel Pipe Size Chart is an essential reference for selecting the correct pipe dimensions, including Nominal Pipe Size (NPS), Outside Diameter (OD), Inside Diameter (ID), wall thickness, and pipe schedule. Understanding these specifications helps engineers, contractors, fabricators, and buyers choose stainless steel pipes that meet pressure, flow, and application requirements while ensuring compliance with international standards.
Whether you require SS 304, SS 316, seamless, or welded stainless steel pipes, selecting the correct size, schedule, and material grade is essential for reliable performance, long service life, and cost-effective operation.
Need Help Selecting the Right Stainless Steel Pipe?
Choosing the correct pipe size, schedule, and material grade is critical for ensuring safe, efficient, and long-lasting system performance. At Kamal Steels, our technical specialists can help you select the ideal stainless steel pipe based on your operating pressure, temperature, corrosion resistance, and industry application.
Request a free quotation today or contact our team for expert guidance on stainless steel pipe dimensions, specifications, material grades, and the latest pricing.