Round Black Steel Pipe is a high-quality carbon steel pipe with a black surface finish, manufactured through welding processes such as ERW (Electric Resistance Welding). It is widely used in construction, structural engineering, machinery manufacturing, transportation systems and industrial applications. As a professional black steel pipe manufacturer and supplier, we provide ERW black round steel pipes in various outer diameters, wall thicknesses and lengths. Our products are available in different steel grades, including Q195, Q235, Q345, ASTM A53 Grade A/B, API 5L Grade B, S235JR, S355JR and other equivalent materials. The pipes are manufactured according to international standards such as ASTM, EN, DIN, JIS, GB, ISO and BS. Black round steel pipes feature high strength, good weldability, accurate dimensions and reliable mechanical performance. Compared with galvanized pipes, black steel pipes have a natural mill finish and are commonly used in applications where surface coating is not required or additional painting and coating will be applied after installation. Our ERW black steel pipes are widely used for steel structures, scaffolding, mechanical equipment, agricultural facilities, water and gas transportation, fencing, and general industrial projects. We offer customized solutions with different specifications, surface conditions and packaging options according to customer requirements. With strict quality control, advanced production facilities and professional export experience, we supply reliable black round steel pipe products to customers worldwide.









■ Product Parameters
Item | Specification |
Product Name | ERW Black Square & Rectangular Steel Tube / ERW Black Hollow Section |
Standards | ASTM, EN, DIN, GB, ISO, JIS, BS, ANSI, etc. |
Material Grade | Q195, Q235, Q345, 10#–45#, ASTM Gr.A, Gr.B, Gr.50, DIN S235JR, JIS SS400, JIS SPHC, BS 040A10, etc. |
Shape | Square, Rectangular |
Outer Size | 10 × 10 mm – 500 × 500 mm (Custom sizes available) |
Wall Thickness | 0.6–25 mm or according to customer requirements |
Length | 5.5 m, 5.8 m, 6 m, 11.8 m, 12 m, or customized |
Surface Finish | Bare Surface, Lightly Oiled, Black Painted, or according to customer requirements |
Manufacturing Process | High-Frequency Electric Resistance Welded (ERW), Cold Formed from Hot-Rolled Steel Strip |
Ends | Plain End, Beveled End, or Threaded (Optional) |
Inspection | Chemical Composition, Mechanical Properties, Dimensional Inspection, Weld Inspection |
Applications | Construction, Steel Structures, Machinery Manufacturing, Furniture, Greenhouse Frames, Fence Systems, Mechanical Engineering, Infrastructure Projects, Oil & Gas, Fluid Transportation (Non-pressure), Agricultural Equipment |
Package | Standard export seaworthy packing:• Bundles fastened with steel strips• Plastic wrapping if required• Or according to customer's requirements |
Delivery Time | According to order quantity, typically 7–20 days after receiving the deposit. |
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■ FAQ
Q: Are you a trading company or a manufacturer ?
A: We are manufacturer. Every month, we do a procurement for a massive number of steel material from Chinese state owned mill. The total value of steel processing equipment is more than 30 million dollars. Our major products cover all category of steel industry, and it is totally compatible to all kind of world steel standard.
Q: Do you have large amount of steel products in stock ?
A: Yes, we do. In large-scale indoor warehouses, the total stock value is over 150 millions dollar.
Q: Do you provide the samples ? Free or Extra ?
A: It is free, depend on the value of the sample. The cost of the freight would be charge.
Q: How long is the delivery time ?
A: Officially, it is within 7 days. Actually, we can deliver within 3 days. Customized products or non-standard size products would be taken 10-30 days to deliver, depend on the production cycle. Generally, most of the products finished and delivered within 20 days.
Q: Do you accept the third party inspection ?
A: Absolutely yes!
Q: How could you guarantee your products ?
A: Each batch of products must have its own factory inspection report. If the third-party inspection report of the product you purchased does not match our factory inspection report, we will resend the goods, and we will carry all the costs by ourselves.
Q: How can I get your quotation as soon as possible ?
A: You may have many methods to contact us. Email and fax will be checked within 12 hours, and Skype, WeChat and WhatsApp will be online in 24/7. Please send us your requirement, attaching specification (Steel grade, dimension, quantity, destination port) or any you are concerned, you will obtain a competitive price and supply solution soon.
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