Welded Steel Pipe Manufacturer & Supplier – Sino East Steel Group
Sino East Steel Group is a professional welded steel pipe manufacturer and supplier headquartered in Tianjin, China. Since 2008, we have exported ERW (electric resistance welded) steel pipes to more than 80 countries across the Middle East, Southeast Asia, Africa, Europe and the Americas. As a factory-direct supplier with our own high-frequency ERW production lines, we eliminate middleman costs and deliver certified welded pipes at competitive wholesale prices, with MOQ starting from 5 tons and a standard 15–25 day delivery window.
ERW welded pipe is produced by cold-forming steel strip into a tubular shape and joining the edges with high-frequency electric resistance welding, followed by heat treatment of the weld zone to restore full strength. The result is a pipe with a precise, uniform weld seam and excellent dimensional accuracy, at a significantly lower cost than seamless pipe for the same service. Our plant covers 50,000 m² with dedicated slitting, forming, ERW welding, sizing, straightening, hydrostatic testing and galvanizing lines, supporting an annual output of over 120,000 tons of welded pipe. Whether you are a scaffolding supplier, a fence manufacturer, a water utility or a national distributor, our export team offers one-stop sourcing: size selection, standard compliance, surface finish, end preparation, packing and sea freight.
Why Choose Sino East Steel Group as Your Welded Pipe Supplier?
International buyers evaluate a welded steel pipe supplier on four factors: product quality, certification, price stability and delivery reliability. The following sections explain how Sino East Steel Group performs on each of them, and why thousands of global buyers choose us as their long-term welded steel pipe manufacturer and supplier.
1. Factory-Direct Manufacturing, No Middlemen
We are not a trading company. Our factory directly controls the entire process from strip purchasing, slitting, forming, high-frequency welding, heat treatment, sizing and straightening to final hydrostatic testing. This vertical integration allows us to offer prices that are typically 5–10% lower than trading companies while maintaining consistent quality, because there is no broker margin in the supply chain. When you buy from Sino East Steel Group, you buy directly from the production source, which also means faster communication, faster quotations and faster problem-solving during the whole cooperation period.
2. Full International Standards Compliance
Our welded pipes are manufactured and tested according to internationally recognized standards, including ASTM A53, API 5L, ASTM A252, EN 10217, EN 10219, BS 1387, JIS G3444 and GB/T 3091. Each batch is accompanied by a mill test certificate (MTC) with chemical composition and mechanical property data, allowing customs clearance and third-party inspection to proceed smoothly. Our quality management system is certified to ISO 9001:2015, and our export documentation team is experienced in preparing certificates of origin and all shipping documents needed for letter of credit transactions.
3. Stable Quality with Multi-Step Inspection
Quality is built through process control, not just final inspection. Our quality control system covers five key checkpoints: incoming strip verification, forming and welding parameters, weld seam heat treatment, non-destructive testing and dimensional measurement. Every production lot undergoes chemical analysis, tensile testing, flattening tests, bend tests, weld seam eddy current testing and hydrostatic testing in accordance with the requested standard. We also accept third-party inspection by SGS, BV or Intertek before shipment, at the buyer’s request, and we welcome overseas buyers to visit our factory in Tianjin to witness the production process in person.
4. Flexible Supply for All Project Scales
From a 5-ton trial order for local distributors to 4,000-ton infrastructure project deliveries, our production scheduling and warehouse stock (normally 10,000–15,000 tons of finished welded pipes) allow us to support urgent orders and staggered deliveries across multiple shipments. Our sales engineers work with buyers to split large orders into weekly or monthly delivery schedules, which reduces the buyer’s warehousing cost and keeps construction sites running without interruption. For project tenders, we can also provide pre-qualification documents, technical datasheets and reference lists from completed projects.
Welded Steel Pipe Product Range
ERW Carbon Steel Pipe
Our core product is high-frequency ERW carbon steel pipe in diameters from 1/2″ to 24″ (21.3 mm to 610 mm), with wall thicknesses from 1.5 mm to 20.0 mm. ERW pipe is supplied black, varnished, oiled or hot-dip galvanized, with plain, beveled, threaded or grooved ends. It is the most economical certified pipe solution for water, gas, scaffolding, fence, structural and mechanical applications, and our ERW lines can run both standard and custom sizes with fast changeover, giving buyers short lead times even for non-standard specifications.
Black Welded Steel Pipe (Sch 40 / Sch 80)
Black welded pipe with a mill-scale or black-painted surface is the workhorse of plumbing, sprinkler, HVAC and structural markets. We supply black ERW pipe to ASTM A53 Gr.B and API 5L Gr.B, in schedules 10 to 160, with plain or threaded ends. Black pipe is ideal for buyers who will paint, coat or thread the pipe themselves, and it offers the lowest material cost of any certified pipe product. Popular sizes such as 1/2″, 3/4″, 1″, 2″ and 4″ are kept in continuous stock, allowing 48-hour dispatch for urgent orders.
Galvanized Welded Steel Pipe
We supply hot-dip galvanized welded pipe with a zinc coating of 60–100 μm for outdoor and corrosive environments, and pre-galvanized pipe with a smoother 20–60 μm coating for indoor applications. Galvanized welded pipe is the standard choice for scaffolding, fence posts, handrails, greenhouse frames, solar mounting structures and water transmission in exposed locations. Coating weight and thickness can be verified with the mill test certificate, and we can arrange independent coating thickness inspection before shipment.
Structural Welded Pipe (ASTM A252 / EN 10219)
For foundation piling and structural applications, we supply welded pipe to ASTM A252 Grades 2 and 3 and EN 10219 S235JR/S355JR. Structural pipe can be supplied in large diameters, thick walls and long lengths, with beveled ends for field welding. Applications include building columns, bridge foundations, piling, marine structures and heavy machinery frames, where welded pipe offers the best strength-to-cost ratio among structural tubular products.
Welded Steel Pipe Specifications
| Parameter | Available Range |
|---|---|
| Outer Diameter | 1/2″ to 24″ (21.3 mm – 610 mm) |
| Wall Thickness | 1.5 mm – 20.0 mm (SCH 10 to SCH 160) |
| Standard Length | 6 m, 12 m (21 ft), or custom cut |
| Weld Process | High-Frequency Electric Resistance Welding (ERW) |
| Standards | ASTM A53, API 5L, ASTM A252, EN 10217, EN 10219, BS 1387, JIS G3444, GB/T 3091 |
| Steel Grade | Q195, Q215, Q235, Q345, A53 Gr.B, S235JR, S355JR, API 5L Gr.B |
| Pipe Ends | Plain End, Beveled End, Threaded & Coupled, Grooved |
| Surface Finish | Black, Varnished, Oiled, Hot-Dip Galvanized, Pre-Galvanized |
| Testing | Eddy Current Weld Inspection, Hydrostatic Test, Flattening/Bend Test |
| Certification | ISO 9001, Mill Test Certificate, SGS/BV/Intertek inspection available |
Typical Weight Reference (SCH 40)
| Nominal Size | OD (mm) | Wall (mm) | Weight (lb/ft) | Weight (kg/m) |
|---|---|---|---|---|
| 1/2″ | 21.3 | 2.77 | 1.27 | 1.27 |
| 3/4″ | 26.7 | 2.87 | 1.69 | 1.69 |
| 1″ | 33.4 | 3.38 | 2.50 | 2.50 |
| 1-1/2″ | 48.3 | 3.68 | 3.63 | 3.63 |
| 2″ | 60.3 | 3.91 | 4.74 | 4.74 |
| 3″ | 88.9 | 5.49 | 8.92 | 8.92 |
| 4″ | 114.3 | 6.02 | 12.84 | 12.84 |
| 6″ | 168.3 | 7.11 | 23.35 | 23.35 |
Typical Applications of Welded Steel Pipe
- Water & gas distribution – municipal water lines, gas distribution networks, irrigation systems
- Scaffolding & construction – scaffolding tubes, handrails, structural supports, formwork props
- Fencing & agriculture – fence posts, gates, greenhouse frames, livestock enclosures
- HVAC & plumbing – sprinkler systems, ventilation ducts, drain and vent lines
- Oil, gas & mining – low-pressure gathering lines, ventilation pipes, conveyor structures
- Machinery & equipment – frames, rollers, conveyors, agricultural machinery
ERW Welded vs. Seamless Pipe: Choosing the Right Product
ERW welded pipe and seamless pipe serve different segments of the market, and choosing correctly saves money without compromising safety. ERW pipe is produced from strip with a high-frequency welded seam and offers the best cost efficiency for diameters up to 24 inches in low-to-medium pressure service. Modern ERW mills with weld seam heat treatment and full NDT produce a weld zone with strength equal to the parent metal, which is why ERW pipe is accepted by ASTM A53, API 5L and EN 10217 for a wide range of pressure applications. Seamless pipe remains the preferred choice for the highest-pressure, highest-temperature and sour-service applications, where any weld seam is considered a risk regardless of test results. As a general guide, ERW pipe is recommended for water, gas, scaffolding, structural and general mechanical service, while seamless is specified for boiler tubes, hydraulic systems, downhole equipment and critical process piping. Our sales engineers help buyers evaluate both options against the actual operating pressure, temperature, fluid and code requirements, and confirm the most cost-effective specification before quotation.
How We Ensure Reliable Export Service
Export Experience Across 80+ Countries
Since our first export shipment in the 1990s, we have delivered welded steel pipes to distributors, fabricators and project owners in the Middle East, Southeast Asia, Africa, South America, Europe and North America. Our team understands the documentation, packaging and shipping requirements of different destination countries, including the Middle East SASO/IECEE certification requirements, the European CE marking requirements and the African market’s preference for bundled, waterproof-packed pipes suitable for long sea voyages and tropical climates.
Professional Export Documentation
Every export order is supported by a complete documentation set: commercial invoice, packing list, bill of lading, mill test certificate, certificate of origin (CO or COO), and, where applicable, insurance certificate and pre-shipment inspection report. For letter of credit (L/C) transactions, our documentation team ensures that all documents are presented exactly as required by the L/C terms, minimizing the risk of discrepancies and payment delays.
Flexible Payment and Incoterms
We support flexible payment terms including T/T (30% deposit and 70% balance before shipment), L/C at sight for large orders, and in some cases D/P for established customers. Regarding incoterms, we quote on EXW, FOB Tianjin, CFR or CIF basis according to the buyer’s preference, and our logistics partners provide competitive sea freight rates to major ports worldwide, including Jebel Ali, Rotterdam, Singapore, Lagos, Mombasa and Santos.
Pricing, MOQ & Delivery
- Price Range: USD 480 – 800 per ton (FOB Tianjin), depending on size, wall thickness, surface finish and order quantity. We provide a firm quotation within 24 hours.
- MOQ: 5 tons for stock sizes; 20 tons for customized specifications.
- Payment Terms: T/T (30% deposit, 70% before shipment) or L/C at sight for large orders.
- Delivery: 15–25 days after deposit, depending on quantity and destination port.
- Packing: Hexagonal bundles with steel straps, waterproof wrapping, or wooden crates for small diameters.
- Port of Loading: Tianjin Xingang Port, China (nearest port to our factory).
Buyer’s Guide: How to Choose a Reliable Welded Pipe Supplier
Choosing the right supplier is as important as choosing the right product. A reliable welded steel pipe supplier should be able to answer five questions clearly: First, which standard and grade is the pipe actually manufactured and tested to, and can the supplier provide the mill test certificate? Second, is the weld seam non-destructively tested, and what NDT method is used? Third, what is the actual lead time from deposit to port of loading? Fourth, how are pipes packed to prevent rust and end damage during sea transport? And fifth, what happens if the quality does not meet the contract specification after arrival? At Sino East Steel Group, we answer all five questions in writing within 24 hours of your inquiry, and we stand behind every shipment with a clear quality guarantee. We recommend every buyer request a mill test certificate with each shipment and, for large orders, arrange third-party inspection before shipment to protect both parties’ interests.
How to Get a Quotation
To receive an accurate factory quotation within 24 hours, please provide the following information: (1) outer diameter and wall thickness or schedule, (2) length and quantity, (3) standard and steel grade, (4) surface finish and end preparation, and (5) destination port. Our export sales engineers will confirm availability, price and delivery schedule, and send you a formal proforma invoice with mill test certificate samples.
Frequently Asked Questions (FAQ)
Q1: What is ERW steel pipe?
ERW (electric resistance welded) pipe is formed from steel strip and joined with a high-frequency electric resistance weld. The weld zone is heat treated to restore full strength, and the seam is tested by eddy current and hydrostatic methods, making ERW pipe suitable for most water, gas and structural applications.
Q2: Is ERW pipe as strong as seamless pipe?
For the same grade and wall thickness, ERW pipe has equivalent tensile strength because the weld zone is heat treated and the entire pipe meets the same chemical and mechanical requirements of standards such as ASTM A53 and API 5L. Seamless pipe is chosen for the most critical high-pressure and sour-service applications, not because of higher strength, but because there is no weld seam at all.
Q3: Do you supply galvanized welded pipe?
Yes. We supply hot-dip galvanized welded pipe with 60-100 um zinc coating for outdoor service, and pre-galvanized pipe with a smoother 20-60 um coating for indoor applications. Coating weight can be verified with the mill test certificate.
Q4: Can you provide threaded and coupled (T&C) ends?
Yes. We supply plain, beveled, threaded and coupled, and grooved ends per BS 1387, ASTM A53 or API 5L requirements, complete with couplings and sockets where specified.
Q5: What is the MOQ for welded steel pipe?
Our MOQ is 5 tons for standard stock sizes and 20 tons for customized specifications. Trial orders help buyers verify our quality and delivery before committing to larger volumes.
Q6: Do you supply welded pipe for scaffolding and piling projects?
Yes. We are a regular supplier of ERW scaffolding tubes and ASTM A252 welded pipe piles, with project-level pricing, custom lengths and fast delivery scheduling.
Contact Sino East Steel Group today – our sales engineers will respond with a factory-direct quotation and technical support within 24 hours.