MS Round Pipe – Mild Steel Round Pipe is circular‑section steel pipe manufactured from low‑carbon steel with carbon content below 0.25%. It delivers good ductility, outstanding weldability and prominent cost advantages. As the most‑consumed and cost‑effective carbon structural pipe, it is the universal tubing for construction, machinery and fluid transmission sectors, and also serves as the base material for galvanized round pipe and zinc‑aluminum coated pipe.
Glory Steel is a professional manufacturer & foreign‑trade supplier of MS Round Pipe. We mainly supply mainstream low‑carbon steel grades: Q195, Q235B, S235JR. Both welded pipe and seamless pipe are available, covering full range of outer diameters and wall thicknesses. Complete mechanical processing and customized surface finishes are provided.
Specifications
| Item | Mild Steel Round Pipe |
|---|---|
| Outer Diameter | 12.7mm‑325mm (1/2”‑12”) |
| Wall Thickness | ≥1.0mm |
| Length | 1m‑12m, custom cutting & bespoke lengths supported |
| Material Grade | Q195, Q235B, S235JR, SS400 / STK400, St33 / S185, GOST 8732 St20 / 08ps |
| Surface Condition | Black finish, descaled bright finish, painted, hot‑dip galvanized, electro‑galvanized |
| Processing Service | Cut‑to‑length, deburring, end facing & chamfering, drilling, bending, threading, polishing & derusting, anti‑corrosion spraying |
| Manufacturing Process | ERW Welded / Seamless |
Theoretical Weight Formula
W (kg/m) = (D − t) × t × 0.02466 D = outer diameter in mm; t = wall thickness in mm.
Common Sizes & Theoretical Weight Table
| Nominal Size (NB) | OD(mm) | WT(mm) | Weight (kg/m) | Weight (kg/ft) | Weight per 6m (kg) |
|---|---|---|---|---|---|
| 15 | 21.3 | 2.0 | 0.95 | 0.29 | 5.7 |
| 40 | 48.3 | 4.0 | 4.37 | 1.33 | 26.2 |
| 50 | 60.3 | 3.2 | 4.51 | 1.37 | 27.1 |
| 80 | 88.9 | 4.0 | 8.38 | 2.55 | 50.3 |
| 100 | 114.3 | 4.5 | 12.19 | 3.72 | 73.1 |
| 150 | 168.3 | 5.0 | 20.14 | 6.14 | 120.8 |
Key Features
- Excellent Weldability: Low carbon content (≤0.25%) allows welding without preheating, with no hardening tendency after welding. It supports easy cutting, bending, welding, turning and other fabrication operations.
- Stable Structural Performance: Base material meets standard tensile strength and yield strength, good compression & torsion resistance, ideal base material for ERW welded tubes and various welded structures.
- Superior Cost‑Performance: High production efficiency and high material utilization rate, ranking among the lowest‑cost steel pipe products. It can be applied in black condition or used as substrate for galvanizing, delivering remarkable cost advantages.
- Wide Compatibility: Standards IS 1161 / IS 1239 are widely recognized across Middle East, Southeast Asia and Africa. It fits most standard carbon‑steel pipe fittings directly.
International Material Grade Parameter Table
| Standard | Grade | Tensile Strength | Yield Strength |
|---|---|---|---|
| GB (China) | Q195 | 315‑430 MPa | ≥195 MPa |
| GB (China) | Q235B | 375‑500 MPa | ≥235 MPa |
| EN (Europe) | S235JR | 360‑510 MPa | ≥235 MPa |
| JIS (Japan) | SS400 / STK400 | 400‑510 MPa | ≥245 MPa |
| DIN (Germany) | St33 / S185 | 310‑430 MPa | ≥185 MPa |
| GOST (Russia) | GOST 8732 St20 / 08ps | 360‑480 MPa | ≥225 MPa |
Main Surface Treatment Options
- Black Pipe: Mill original finish. Used directly for indoor structures or as substrate for coated / galvanized tubes.
- Descaled Bright Finish: Mechanically polished & scale‑free, smooth surface for subsequent precision fabrication.
- Hot‑dip Galvanized: Covered with a metallic zinc layer, greatly enhanced anti‑corrosion performance and extended service life.
- Painted / Plastic Coated: Anti‑rust paint or powder plastic coating for UV‑resistance and corrosion protection, longer service life.
Production Process
Raw material inspection → Hot rolling forming (Seamless / ERW welding) → Sizing & straightening → Cut‑to‑length → End deburring & finishing → Surface derusting → Optional painting / hot‑dip galvanizing → Dimensional inspection → Non‑destructive testing → Anti‑rust packing & shipment
Manufacturing Process Types
Mild steel round pipes are categorized into two main types based on the manufacturing process: seamless pipes and welded pipes. Welded pipes are further classified into three types—ERW, LSAW, and SSAW—based on diameter and wall thickness.
- Seamless Mild Steel Round Pipe: Produced by piercing a steel billet; features uniform material composition throughout and no weld seams; suitable for thick-walled applications and high-pressure conditions.
- Welded Mild Steel Round Pipe
- ERW MS Round Pipe: High-frequency electric resistance welded (longitudinal seam); suitable for small-to-medium diameters (≤ 24″) and wall thicknesses ranging from thin to medium-thick.
- LSAW MS Round Pipe: Longitudinal submerged arc welded; suitable for medium-to-large diameters (16″–60″) and wall thicknesses ranging from medium-thick to thick.
- SSAW MS Round Pipe: Spiral submerged arc welded; suitable for large diameters (20″–100″+) and thick-walled applications.
Applications
- Fluid Conveyance: Civil water supply & drainage, low‑pressure gas pipeline, agricultural irrigation pipeline, HVAC systems.
- Construction Sector: Scaffolding support, pile casing, steel framework, guardrail posts & rails.
- Industrial Field: Cable conduit, equipment protective frames, general transmission pipelines, automotive tubing.
- Hardware Fabrication: Furniture tubing, fitness equipment frames and small hardware structural components; widely adopted base raw material for deep‑processing industries.
Material & Working Condition Recommendation
- Select Q195: Light‑duty structures, furniture accessories, heavy bending fabrication.
- Select Q235B: Load‑bearing engineering projects and general industrial scenarios for universal usage.
- Select S235JR: Projects for European, Middle Eastern, and African markets.
- Select coated pipes: Long‑term outdoor exposure or indoor anti‑corrosion working conditions.
FAQ
Q1: What is the difference between MS Round Pipe and GI Pipe?
A: GI Pipe is finished by hot‑dip galvanizing treatment based on MS Round Pipe substrate. MS pipe is bare black tube; GI pipe comes with zinc coating for better corrosion resistance.
Q2: Can MS round pipe be used outdoors long‑term?
A: Original black MS pipe provides no rust protection and tends to oxidize and rust outdoors. For long‑term outdoor service, painting or hot‑dip galvanizing treatment is required to improve weather resistance.
Q3: What is the difference between Q235B and S235JR?
A: Both deliver similar mechanical strength and fabrication performance; differences lie in applicable standards. Q235B is Chinese‑standard general carbon steel for domestic engineering projects; S235JR complies with European standards and meets international export inspection specifications.
Q4: What processing services are available?
A: Cut‑to‑length, threading, beveling, end chamfering, polishing, galvanizing, painting and other custom services.
Glory Steel Plant, located in Tianjin, China, is an ISO 9001, ISO 14001, and CE‑certified factory with an annual output of 100,000 tons. Specializes in manufacturing MS seamless round pipes‑available in various specifications and wall thicknesses‑as well as welded carbon steel pipes. We provide custom processing and OEM/ODM solutions. With stable quality and comprehensive service, we export to over 120 countries.
