Description
Factory-Direct ZAM Tube Supply — All Q195, Q235, Q355 grades in 20–500 mm side lengths held in Jinan yard for immediate dispatch.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195/Q235/Q355 ZAM Coated Square and Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (ZAM Coated) |
| Steel Grade | Q195, Q235, Q355 |
| Standard | ASTM, JIS, GB, EN, AISI, DIN |
| Section Shape | Square / Rectangular |
| Size Range | 20 mm – 500 mm (outer side length) |
| Wall Thickness | 1 mm – 30 mm |
| Length | 5.8 m – 12 m (customizable) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | ZAM (Zinc-Aluminum-Magnesium alloy coating) / Hot-Dip Galvanized |
| Coating | AZ61 – AZ80 (Aluminium content 55%) |
| Zinc Coating | 30 g – 275 g/m² |
| Spangle Type | Zero Spangle |
| Ends | With or without end protectors (caps) |
| Processing Service | Welding, Punching, Cutting, Bending |
| Application | Solar mounting systems, Steel structures, Construction frames, Machinery, Infrastructure support beams |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Solar EPC Contractors | Ground-mounted racking posts, rooftop ballast frames, tracker support beams |
| Steel Structure Fabricators | Portal frame columns, bracing members, purlin systems for industrial sheds |
| Construction Companies | Curtain wall sub-frames, facade support grids, mezzanine beams |
| Machinery Manufacturers | Agricultural equipment chassis, conveyor support structures, crane booms |
| Infrastructure Projects | Highway sound barrier posts, fencing rails, utility pole bases in coastal zones |
Where ZAM Coating Outperforms Standard Galvanizing on Solar Mounting Frames
Standard galvanized coatings crack at cut edges; ZAM self-heals.
Solar mounting systems sit exposed for 25+ years — coastal salt spray, industrial fallout, and humidity cycles eat through conventional zinc layers fast. When a galvanized tube gets drilled or cut on-site, the bare steel at the hole edge becomes the first corrosion point. ZAM alloy coating (AZ61–AZ80 with 55% aluminium) forms a dense zinc-aluminum-magnesium hydroxide layer that migrates to cut edges and weld zones, sealing them against red rust. Project engineers specifying a ZAM coated square and rectangular steel tube for solar racking avoid the field-touch-up painting that delays commissioning. [NEED_CITE: Zinc-Aluminum-Magnesium coating self-healing mechanism at cut edges]
Matching Solar Racking Load Paths to Q355 Grade Capacity
Ground-mounted solar arrays in Southeast Asia and the Middle East demand support beams that resist both corrosion and cyclic wind loading. Q355 grade ZAM coated square and rectangular steel tube delivers the yield strength needed for 6-meter cantilever spans without stepping up to heavier wall sections — keeping racking weight and foundation costs down. The ZAM surface survives the punching and drilling required for module clamp connections without exposing raw steel, which is why EPC contractors increasingly replace HDG tube with ZAM-coated sections for coastal and tropical installations.
Structural Compliance and Certification Requirements
Solar mounting structures fall under EN 1993-1-3 (design of cold-formed members) in Europe and ASCE 7 load criteria in North America — both require verified material properties and traceable mill certificates. A ZAM coated square and rectangular steel tube supplied with EN 10219 dimensional tolerance and EN 3.1 MTC clears EU customs without re-inspection delays. For Middle East and African projects, Lloyd’s CE certification and Singapore FPC approval confirm that the tube meets regulated-market import standards before it leaves the mill. [NEED_CITE: EN 10219 cold-formed structural hollow section tolerance requirements]
Understanding Q195, Q235, and Q355 Grade Selection
The Chinese Q-grade system maps roughly to European S-grades and American ASTM A500 grades: Q195 suits light-duty fencing and non-structural bracing; Q235 covers general construction frames and solar racking purlins; Q355 handles primary structural members where higher yield strength reduces section size. ERW welding produces a consistent longitudinal seam suitable for square and rectangular profiles up to 500 mm, with tighter dimensional tolerance than SSAW for smaller sections. ZAM coating at AZ61–AZ80 provides 3–6 times the salt-spray resistance of equivalent-thickness hot-dip galvanizing, making it the preferred surface for outdoor structural tubes in aggressive environments. [NEED_CITE: Steel grade equivalence between GB Q-series and EN S-series standards]
The Hidden Cost of Negative Tolerance on Structural Tube Orders
Specifying Q355 grade means nothing if the delivered wall thickness runs minus 10% — the section modulus drops, deflection limits fail, and the engineer rejects the batch at installation. Material certificates listing “theoretical weight” instead of actual measured thickness mask this problem until the tubes reach the site. A ZAM coated square and rectangular steel tube ordered with guaranteed minimum thickness and verified by third-party inspection (SGS/BV) prevents the air-freight replacement costs and project delays that follow tolerance disputes. [NEED_CITE: Dimensional tolerance requirements for structural hollow sections per EN 10219]
Why Procurement Teams Source ZAM Tube Directly from Our Jinan Mill
We roll ERW square and rectangular sections from 20 mm to 500 mm in-house, then apply ZAM coating on our own line — no trading company markup between the mill and your container. Our physical and chemical laboratory tests coating adhesion, salt-spray resistance, and weld-seam integrity before release, so every ZAM coated square and rectangular steel tube ships with a mill test certificate you can trust. With 2,800+ specifications in stock, we fill the off-standard sizes (heavy wall, non-standard length, odd aspect ratio) that spot-buy traders cannot source. Lloyd’s CE, ISO 9001, and Singapore FPC certifications travel with every shipment, and our loading crew uses purpose-built cradles to prevent ZAM surface scratching during container stuffing.
Documentation & Compliance
- Mill test certificate documenting Q195/Q235/Q355 chemical composition and mechanical properties per GB/T 6728 or EN 10219
- CE certificate (EN 10210/EN 10219) for EU customs clearance of structural hollow sections
- ISO 9001:2015 quality management certificate covering ZAM coating process control
- SGS or BV third-party inspection report verifying coating thickness (AZ61–AZ80) and dimensional tolerance
- Heat number traceability from steel coil to finished ZAM coated square and rectangular steel tube
- Export documents: packing list, bill of lading, certificate of origin, and commercial invoice
Packaging, Loading & Delivery
- ZAM coated tubes bundled with galvanized steel strips and edge protectors to preserve the zinc-aluminum-magnesium coating during ocean transit
- End caps fitted on all Q195/Q235/Q355 sections to prevent moisture ingress and internal corrosion in 5.8 m – 12 m lengths
- Container loading optimized for 20 ft and 40 ft OT/FR: 500 mm square tubes loaded flat with timber spacers; smaller sections nested to maximize payload
- Custom cutting to project-specific lengths available — reduces on-site waste and welding for solar racking fabricators
- Heat number and steel grade stenciled on each tube end for site traceability and MTC cross-referencing
- FOB Jinan/Qingdao, CIF destination port, or DDP door delivery arranged with forwarders experienced in steel tube shipments
Start Your ZAM Tube Inquiry with Drawings and Quantities
Send your solar mounting layout or structural steel schedule with side lengths, wall thickness, steel grade (Q195/Q235/Q355), and total tonnage — we return a detailed quotation with unit price, lead time, and mill test certificate sample within 12 hours. Non-standard sizes, pre-punching, and bending services are quoted alongside the base tube price so you see the full fabrication cost upfront.
Request ZAM Tube Pricing and Mill Certificates
Submit your specification sheet to admin@sdxjypipe.com or message +86 188 5315 7756 (WhatsApp/WeChat) for a quotation with MTC and third-party inspection options.
Frequently Asked Questions
Q: What is ZAM coating and how does it compare to hot-dip galvanized?
A: ZAM (Zinc-Aluminum-Magnesium) coating contains 55% aluminium and forms a denser, more corrosion-resistant layer than pure zinc galvanizing. It self-heals at cut edges and provides 3–6 times the salt-spray resistance of equivalent-thickness HDG, making it ideal for solar mounting and outdoor structural applications.
Q: Can ZAM coated tubes be welded and cut on-site without losing corrosion protection?
A: Yes. The ZAM alloy’s self-healing property means that cut edges and weld zones form a protective zinc-aluminum-magnesium hydroxide layer when exposed to moisture, sealing against corrosion without field painting.
Q: What steel grades are available for solar mounting structural tubes?
A: We supply Q195, Q235, and Q355 grades in ZAM-coated square and rectangular sections. Q235 covers most racking purlins and bracing; Q355 is specified for primary support beams and cantilever arms requiring higher yield strength.
Q: Do you provide custom sizes and fabrication services?
A: Yes. We offer cutting to length, punching, welding, and bending for ZAM coated square and rectangular steel tube. Non-standard side lengths and wall thicknesses are available within the 20–500 mm and 1–30 mm range.
Q: What certifications are provided for EU and international markets?
A: We supply CE certification (EN 10210/EN 10219), ISO 9001:2015, Singapore FPC, and third-party inspection reports (SGS/BV) with every shipment. Mill test certificates conform to EN 10204 3.1.
