Mild steel pipe (MS pipe) is a type of carbon steel pipe made from low-carbon steel. It typically contains a small percentage of carbon (below 0.25%) along with elements such as silicon, manganese, phosphorus, and sulfur.
Because of its excellent ductility, weldability, and cost-effectiveness, mild steel pipe is widely used in structural, mechanical, and fluid transport applications.
MS pipes can be produced as either seamless or welded types, allowing them to meet different pressure ratings, performance needs, and operating environments.
Common MS Pipe Standards
The standards governing mild steel pipes vary across regions and industries. Below are some of the most widely adopted specifications:
1. Indian Standards
IS 1239, IS 161, IS 3589, IS 4270, IS 1978, IS 3601, etc.—cover general, pressure, and structural applications.
2. American Standards
ASTM A53, ASTM A135, ASTM A795, ASTM A523, etc.—used for carbon steel pipes in liquid, gas, and fire protection systems.
3. British Standards
BS 1387, BS 3601, BS 6323, etc.—apply to threaded and structural steel pipes.
4. European Standards
EN 10255, EN 10219, EN 10217, EN 10296, etc.—specify non-alloy structural, pressure, and welded steel pipes.
5. Japanese Standards
JIS G 3444, JIS G 3452, JIS G 3454, JIS G 3455, etc.—for structural, general, and pressure piping.
6. Australian Standards
AS 1074, AS 1163, AS 1450, etc.—for low-carbon steel pipes used in piping and structural applications.
These standards define the dimensions, weight, chemical composition, mechanical properties, and testing methods of MS pipes.
The appropriate standard is chosen based on the intended use, project requirements, and regional regulations.
Advantages of Mild Steel Pipe
1. Excellent Ductility
MS pipes are highly ductile and can be bent or shaped easily, making them ideal for manufacturing and fabrication.
Their elongation rate of 20%–25% allows better formability than high-carbon or alloy steels.
2. Cost-Effectiveness
Because of their low carbon content, MS pipes are cheaper to produce than other steel types such as galvanized or alloy steel pipes, offering great value for large-scale projects.
3. High Pressure Resistance
Seamless mild steel pipes are made from solid billets, heated and rolled into cylindrical shapes.
This process results in superior strength and durability, allowing them to withstand high-pressure fluids and gases—ideal for industrial and energy applications.
4. Recyclability
MS pipes can be recycled and reused as scrap steel. This contributes to sustainability and reduces raw material costs.
5. High Weldability
With carbon content below 0.25%, MS pipes are easy to weld without excessive hardening, ensuring strong and reliable joints in construction and industrial piping.
Disadvantages of Mild Steel Pipe
1. Prone to Rust and Corrosion
Without a protective coating, MS pipes corrode easily when exposed to moisture or chemicals.
Therefore, protective coatings such as paint, galvanizing, or epoxy are recommended.
2. Higher Maintenance Requirements
Due to their tendency to rust, mild steel pipes often require regular maintenance and replacement, especially in humid or corrosive environments.
3. Not Suitable for Drinking Water
Mild steel reacts with oxygen in water, forming rust and affecting water quality. Hence, it is not recommended for drinking water systems.
For potable water, galvanized steel pipes or stainless steel pipes should be used.
4. Lower Tensile Strength
With a typical tensile strength of 330–410 MPa, mild steel is less strong and rigid than alloy steels (>600 MPa), making it more prone to deformation or fracture under heavy loads.
Applications of Mild Steel Pipes
Fire Protection Systems – Transporting water to hydrants and sprinkler systems.
HVAC Systems – Carrying hot/cold water and air in heating, ventilation, and air-conditioning setups.
Piping Systems – Used in plumbing and wastewater transport.
Structural Applications – Building frameworks, bridges, and infrastructure supports.
Mechanical Applications – Conveying fluids and gases in machinery and equipment.
Automotive Applications – Used in exhaust systems and mechanical components.
Agricultural Applications – Ideal for irrigation and drainage systems.
FAQ
1. What Is the Lifespan of MS Pipes?
Untreated MS pipes typically last 5–10 years in humid environments.
When coated with galvanizing, epoxy, or internal linings, their lifespan can exceed 25 years.
2. Can MS Pipes Be Used for Drinking Water?
No. MS pipes corrode and rust when exposed to water, contaminating the supply.
For drinking water, use galvanized or stainless steel pipes instead.
