MS Pipes & Fittings

Mild Steel (MS) Seamless Pipe

Mild Steel (MS) Seamless Pipes are high-strength industrial components manufactured without any weld joints or seams. Because they lack a "weak point" (the weld), they are the preferred choice for high-pressure and high-temperature environments.

Here are the technical specifications and standards for MS seamless pipes:

1. General Specifications

Size Range: Commonly available from 1/8" to 24" NB (Nominal Bore).
Wall Thickness: Varies by "Schedule" (e.g., SCH 40, 80, 160, XXS). Thicknesses typically range from 1.5 mm to 60 mm.
Length: Standard lengths are 6 meters (20ft), though "Single Random" (4–7m) and "Double Random" (7–12m) lengths are common.
Ends: Plain end, Beveled end (for welding), or Threaded/Screwed.

2. Standard Dimensions (Schedule 40 & 80)

The table below shows the most common specifications for standard (SCH 40) and extra-strong (SCH 80) pipes.

Nominal Size (NB)	Outer Diameter (mm)	SCH 40 Wall Thk (mm)	SCH 80 Wall Thk (mm)	Weight (kg/m - SCH 40)
1/2"	21.3	2.77	3.73	1.27
1"	33.4	3.38	4.55	2.5
2"	60.3	3.91	5.54	5.44
3"	88.9	5.49	7.62	11.29
4"	114.3	6.02	8.56	16.07
6"	168.3	7.11	10.97	28.26

3. Material & Chemical Composition

MS seamless pipes are typically made of low-carbon steel. The most common grade is ASTM A106 Grade B.

Carbon (C): 0.25% – 0.30% (Max)
Manganese (Mn): 0.29% – 1.06%
Silicon (Si): 0.10% (Min)
Phosphorus & Sulfur: ≤ 0.035% each

4. Mechanical Properties

For the standard ASTM A106 Grade B material:

Tensile Strength: ≥ 415 MPa (60,000 psi)
Yield Strength: ≥ 240 MPa (35,000 psi)
Elongation: Minimum 30%

5. Common Industry Standards

Depending on your application (oil, gas, water, or structural), you will likely look for one of these standards:

ASTM A106: For high-temperature, high-pressure service.
ASTM A53: For general-purpose fluid transport and steam.
API 5L: Specifically for the oil and natural gas industries.
IS 1239 / IS 3589: Common Indian standards for water, gas, and air lines.