Round steel tubes play a major role in construction, fabrication, engineering structures, and industrial applications. At SG Nirmal Mart, we provide a complete range of Black Round Tubes, Pre-Galvanised (GP) Tubes, and Galvanised (GI) Tubes that match industry standards and project-specific needs.
This guide helps you understand their specifications and ideal uses.

1. Black Round Tubes

Black Round Tubes are widely used for structural and mechanical purposes. They offer strength, durability, and great welding performance.

Specifications:

• NB Series: 15mm to 350mm

• OD Series: 21.3mm to 406.4mm

• Thickness: 1mm to 25mm

• Length: 6 meters standard, custom 4–15 meters

• Grades: ST 210, 240, 310, 355

• Standards: IS 1161, IS 1239, IS 9295

If you want to explore more about our product range, visit the SG Nirmal Mart Home Page.

For bulk orders or custom sizes, you can easily enquire now.

2. Pre-Galvanised (GP) Round Tubes

GP Tubes combine strength with corrosion resistance, making them ideal for interior structures, furniture, light fabrication, and commercial installations.

Specifications:

• NB Series: 15mm to 350mm

• OD Series: 21.3mm to 406.4mm

• Thickness: 1mm to 25mm

• Length: 6 meters standard, custom 4–15 meters

• Standards: IS 1161, IS 1239, IS 3601

To know more about our processing quality and supply capability, check our About Us page.

3. Galvanised (GI) Round Tubes

GI Tubes provide long-lasting protection against corrosion, making them suitable for water lines, outdoor frameworks, fencing, agriculture, solar structures, and more.

Specifications:

• NB Series: 15mm to 350mm

• OD Series: 21.3mm to 406.4mm

• Thickness: 1mm to 25mm

• Length: 6 meters standard, custom 4–8.5 meters

• Grades: ST 210, 240, 310, 355

• End Finish: Plain End, Bevel End, Screwed (SWS), Screwed & Socketed (SS)

• Standards: IS 1161, IS 1239, IS 3601

• Coating Mass: 60 micron, 80 micron

If you need guidance on selecting the right tube, feel free to contact us.

Why Choose SG Nirmal Mart?

From standard sizes to customised lengths, our inventory covers all industrial and project-based requirements. With reliable supply, certified products, and responsive customer support, we ensure smooth and timely delivery.

For project enquiries or quotations, just submit your request on our Enquiry Page.