Choosing the Right Wall Thickness for Galvanized Pipes

Galvanized steel pipes come in a wide variety of specifications and are suitable for different engineering fields and pressure ratings. Below are some common galvanized steel pipe specifications and their corresponding standard ranges for wall thickness. However, please note that the specific wall thickness standards may vary depending on the country and region standards. The ranges provided here are approximate.Schedule 40 Galvanized Pipe is popular because it provides adequate wall thickness for most plumbing, water supply, and light industrial applications.

Galvanized Pipe Wall Thickness Range

The choice of galvanized pipe wall thickness mainly depends on the actual application and required load-bearing capacity.

Generally, the standard wall thickness for galvanized pipes is 2.0mm or 2.5mm, suitable for galvanized steel pipes with an outer diameter of DN15 or less and 26.9mm or less. For lightweight galvanized steel pipes (also known as thin-walled pipes), mainly used for transporting low-pressure fluids such as water and gas, wall thicknesses are generally 1.4mm, 1.6mm, or 1.8mm. For small and medium diameter steel pipes (generally below DN40), commonly used wall thickness standards include 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, 3.2mm, 3.5mm, 3.8mm, and 4.0mm.

In actual production, the common galvanized pipe wall thickness is 0.5mm to 1.5mm. However, it should be noted that an excessively thick galvanized layer may affect the strength and reliability of the pipe; therefore, excessive thickness may increase cost and weight. Therefore, when selecting galvanized pipes, it is necessary to comprehensively consider the usage environment and requirements, and choose the appropriate galvanized pipe wall thickness.

What Does “Wall Thickness” / “Schedule” Mean for Galvanized Pipes

For galvanized steel pipes, wall thickness is often expressed via a “Schedule” (SCH) number — e.g. SCH 40, SCH 80, SCH 160. Higher schedule → thicker wall at the same nominal outside diameter (OD).

The schedule number helps standardize and compare pipes’ wall thickness across different diameters, materials, and manufacturers.

For example: an ERW galvanized pipe with NPS (nominal pipe size) 2″ in SCH 40 might have a wall thickness around 0.154 inches (≈ 3.91 mm), while in SCH 80 it might be 0.218 inches (≈ 5.54 mm) for the same OD.

Thus, choosing the right “schedule” — or wall thickness — is a first essential step before drilling down into exact dimensions.

Standard Nominal Diameters for Galvanized Pipes

Galvanized pipes are available in a wide range of sizes to accommodate different applications. The nominal diameter, often referred to as the nominal pipe size (NPS), is a standardized measurement used to describe the size of a pipe. It's important to note that the nominal diameter is not always the exact measurement of the pipe's inner or outer diameter.
Common nominal diameters for galvanized steel tubing include:
1/8 inch (3.2 mm)
1/4 inch (6.4 mm)
3/8 inch (9.5 mm)
1/2 inch (12.7 mm)
3/4 inch (19.1 mm)
1 inch (25.4 mm)
1 1/4 inch (31.8 mm)
1 1/2 inch (38.1 mm)
2 inch (50.8 mm)
2 1/2 inch (63.5 mm)
3 inch (76.2 mm)
4 inch (101.6 mm)
6 inch (152.4 mm)
8 inch (203.2 mm)
These sizes are commonly used in both residential and commercial applications. Smaller diameters (1/8 inch to 2 inches) are frequently found in household plumbing systems, while larger diameters are often utilized in industrial settings or large-scale water distribution systems.

Common Thickness Standards for Stainless Steel Galvanized Pipes

The thickness standards for stainless steel galvanized pipes are usually specified by national or industry standards. Below are some common thickness standards for stainless steel galvanized pipes:
Standard Wall Thickness: According to national or industry standards, the standard wall thickness of stainless steel galvanized pipes is generally between 0.8mm and 4.0mm. This standard wall thickness is suitable for most conventional applications, such as water supply pipelines and petrochemical pipelines.
Thin Wall Pipe: Thin-walled stainless steel galvanized pipes are generally less than 0.8mm thick and are mainly used in applications with lower weight requirements, such as furniture manufacturing and decoration.
Thick Wall Pipe: Thick-walled stainless steel galvanized pipes are generally greater than 4.0mm thick and are suitable for applications subjected to high temperatures, high pressures, or special working conditions, such as chemical equipment and oil drilling.