Description
Factory-Direct ERW Round Steel Pipe — Q235 ERW round steel pipe rolled and tested in-house, shipped without distributor markup to 50+ countries.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 ERW Round Steel Pipe |
| Product Type | ERW Welded Round Steel Pipe |
| Steel Grade | Q195, Q215, Q235, Q345, 10#, 20#, S235JR, S275JR, S355JR |
| Standard | GB, JIS |
| Section Shape | Round |
| Outer Diameter | 20–200 mm |
| Wall Thickness | Customizable |
| Length | 6 m / 12 m |
| Technique | ERW (Hot Rolled / Cold Rolled) |
| Surface Treatment | Black Painted / Hot Rolled |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Fluid Pipe, Boiler Pipe, Drill Pipe, Hydraulic Pipe, Gas Pipe, Oil Pipe, Chemical Fertilizer Pipe, Structure Pipe |
| MOQ | 25 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Oil & Gas Transport | Gas distribution lines, oil field gathering pipelines, fuel transfer systems |
| Industrial Construction | Structural columns, scaffolding uprights, conveyor frame supports |
| Chemical Processing | Chemical fertilizer plant piping, process fluid transfer lines |
| Mechanical Engineering | Hydraulic cylinder barrels, drill string components, machinery frames |
| Power & Utilities | Boiler feedwater lines, cooling water circulation pipes |
What Wall-Thickness Tolerance Costs on a Fluid Pipeline Order
±1% OD and wall tolerance keeps hydraulic and gas systems within pressure design limits.
When procurement teams order ERW round steel pipe for fluid or gas transport, a wall that runs 8% under nominal — a common negative-tolerance practice at some mills — silently reduces burst pressure and triggers rejection at third-party inspection. I have watched containers sit in a Middle Eastern port for weeks because every piece failed ultrasonic wall measurement. The replacement cost was not just the steel; it was the air-freight, the delayed commissioning, and the contractor’s lost credibility. With our in-house physical and chemical laboratory checking every heat before the container door closes, that scenario does not repeat. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Matching OD 20–200 mm to Fluid and Structural Duty
Small-diameter ERW round steel pipe in the 20–60 mm range serves hydraulic lines and boiler feed systems where internal pressure and weld-seam integrity matter more than section modulus. The 60–200 mm band shifts toward structural framing, scaffolding uprights, and machinery columns — applications where Q235 or Q345 grade provides adequate yield strength at lower cost than seamless alternatives. Our ±1% tolerance holds across this full range, and the plain ends arrive ready for on-site welding, punching, or bending without secondary preparation.
Engineering Compliance and Certification Pathways
Fluid and structural projects in regulated markets demand documentation that matches the steel grade on the drawing. Q235 maps to S235JR under EN standards and roughly to A36 under ASTM — but customs authorities and project inspectors do not accept verbal equivalence; they require a mill test certificate referencing the correct standard code. [NEED_CITE: steel grade equivalence mapping between GB, EN, and ASTM systems] CE certification under EN 10219 or EN 10210 is mandatory for EU structural hollow sections, while Singapore FPC covers Southeast Asian public works. Our factory holds Lloyd’s CE, ISO 9001:2015, and Singapore FPC, and we arrange SGS or BV third-party inspection before shipment so that the paperwork arriving at destination matches the physical cargo.
Understanding ERW Process and Grade Selection
ERW (Electric Resistance Welded) pipe is formed from hot-rolled or cold-rolled coil and welded along the longitudinal seam without filler metal — making it cost-effective for low-to-medium pressure applications and structural use where seamless is not specified. The Q-series grades (Q195 through Q345) follow the Chinese GB system with yield strength increasing across the range; the S-series (S235JR, S275JR, S355JR) follows EN standards with similar progression. For chemical fertilizer plants or oil field gathering lines, 10# or 20# carbon grades offer better weldability and low-temperature toughness. The black painted or hot-rolled surface leaves the pipe ready for hot-dip galvanizing or 3PE coating if the service environment demands corrosion protection beyond indoor or buried conditions.
Hidden Costs of Unverified Grade and Missing Certificates
Ordering ERW round steel pipe without confirmed grade equivalence and valid mill test certificates creates three failure modes at destination: customs detention due to missing CE or EN references, project rejection when the inspector finds chemistry outside the specified grade band, and structural liability if actual yield strength falls below design assumptions. [NEED_CITE: consequences of non-compliant steel imports in EU construction projects] These costs never appear on the original proforma invoice — they surface only after the container is opened, when re-ordering means weeks of delay and the original supplier is unreachable or unwilling to compensate.
Why Procurement Teams Source from Shandong Xin Jiyuan
We operate three ERW production lines covering over 2,800 specifications — meaning your non-standard OD or heavy-wall request likely ships from stock rather than entering a 20-day production queue. Every heat is tested in our in-house physical and chemical laboratory before release, and the mill test certificate travels with the cargo, not as an afterthought emailed weeks later. Our 41 invention patents include China’s original sharp-corner rectangular tube technology, and while this page covers round pipe, the same quality infrastructure backs every section we produce. Full international certifications — ISO 9001:2015, Lloyd’s CE, Singapore FPC, SGS/BV verification — clear customs in EU, North America, Middle East, and Southeast Asian ports without supplementary documentation requests. Professional container loading with anti-damage measures prevents the bending and surface scoring that triggers rejection at destination.
Documentation & Compliance
- Mill test certificate documenting Q235 chemical composition and mechanical properties per GB/T 700, with heat number traceability
- CE certificate under EN 10219 for cold-formed structural hollow sections, required for EU construction projects
- ISO 9001:2015 quality management certificate covering the full ERW production and testing process
- SGS or BV third-party inspection report available before container sealing, covering dimensional and visual checks
- Material traceability by heat number stamped on each pipe end, matching the mill test certificate
- Full customs documentation set: packing list, bill of lading, certificate of origin, and commercial invoice
Packaging, Loading & Delivery
- Black painted Q235 ERW round steel pipe bundled with steel strips and edge protectors to preserve surface finish during ocean transit
- 6 m and 12 m lengths loaded in nested configurations to maximize 20ft and 40ft container payload within the 25-ton MOQ
- Plain-end pipes capped at both ends to prevent moisture ingress and internal corrosion before installation
- Heat number and steel grade stenciled on each bundle tag for on-site identification and inspection matching
- FOB, CIF, and DDP shipping terms available with door-to-door tracking to 50+ countries
- Custom cutting to project-specific lengths available before shipment, reducing on-site waste and secondary processing
Start Your Procurement with Verified Specifications
Submit your OD, wall thickness, steel grade, quantity, and destination port to receive a detailed quotation with unit price, typical production lead times, and the mill test certificate format for your review. Non-standard dimensions and custom lengths are quoted separately with low MOQ flexibility.
Request Quotation and Mill Test Certificate
Send your specifications to admin@sdxjypipe.com or contact us via WhatsApp at +86 188 5315 7756. Our team responds within 12 hours with pricing, certification confirmation, and loading plan.
Frequently Asked Questions
Q: What is the grade equivalence between Q235, S235JR, and ASTM A36?
A: Q235 under GB/T 700 corresponds closely to S235JR under EN 10025 in chemical composition and yield strength. ASTM A36 is a functional equivalent for structural applications, though exact chemistry varies slightly. We provide cross-reference documentation with every mill test certificate.
Q: Can you provide third-party inspection before shipment?
A: Yes. We arrange SGS or BV inspection at our facility before container sealing. The inspection report covers dimensional verification, visual surface check, and witness of mechanical testing if required by your purchase order.
Q: What surface treatment options are available for corrosion protection?
A: Standard delivery is black painted or hot-rolled finish. For outdoor or corrosive environments, we offer hot-dip galvanizing and 3PE coating as secondary processing. Surface treatment is quoted separately and applied before shipment.
Q: What is the minimum order quantity for custom wall thickness?
A: The standard MOQ is 25 tons. For non-standard wall thickness or non-standard lengths outside 6 m and 12 m, we evaluate case by case and typically accommodate smaller trial orders for new customers.
Q: How do you ensure dimensional tolerance meets project requirements?
A: Our in-house physical and chemical laboratory tests every heat for OD, wall thickness, and ovality before release. Tolerance is held at ±1% per the product specification. Results are documented in the mill test certificate and available for third-party verification.
