Description
Full-Range ZAM Tube Manufacturing — From 0.5mm light gauge to 30mm heavy structural walls, all produced on our own ERW lines with in-house ZAM coating.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195/Q235/Q355 Galvanized Magnesium Aluminum Square & Rectangular Steel Tube |
| Product Type | Galvanized Square and Rectangular Steel Tube (ZAM Coated) |
| Steel Grade | Q195, Q235, Q355 |
| Standard | ASTM, JIS, GB |
| Section Shape | Square / Rectangular |
| Size Range | 20×60mm, 40×75mm (custom sizes available) |
| Wall Thickness | 0.5–1.0mm (light gauge); up to 30mm (heavy structural) |
| Length | 5.8m / 6m / 6.4m / 12m (custom cut available) |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | ZAM Coating (Zinc-Aluminum-Magnesium) / Hot-Dip Galvanized (Zinc coating 30–275g/m²) |
| Aluminium Content | 55% |
| Coating Grade | AZ61–AZ80 |
| Spangle Type | Zero Spangle |
| Tolerance | ±1% |
| Ends | With or without plastic caps |
| Processing Service | Welding, Punching, Cutting, Bending |
| Application | Structural pipe / Steel structures / Construction frames / Architectural facades / Curtain wall framing / Machinery frames / Scaffolding |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Facade | Glass curtain wall framing, architectural facade supports, exposed structural columns in coastal commercial buildings |
| Steel Structure | Portal frame warehouses, industrial building purlins and girts, mezzanine floor supports |
| Machinery & Equipment | Conveyor frame structures, equipment support stands, agricultural machinery chassis |
| Infrastructure | Scaffolding systems, sound barrier posts, solar panel mounting structures |
Where ZAM Coating Outperforms Standard Galvanizing on Coastal Projects
Standard hot-dip galvanized tubes begin showing white rust within months in marine environments — ZAM coating’s magnesium content creates self-healing zinc hydroxide at cut edges, extending service life significantly.
I have seen too many facade projects in Dubai and Southeast Asian coastal cities where standard galvanized rectangular tubes developed edge corrosion within a single wet season. The problem is not the zinc thickness itself but the exposed cut edges after on-site welding and drilling. ZAM coated galvanized square rectangular steel tube with 55% aluminium and AZ61–AZ80 coating grade forms a dense magnesium-rich corrosion product that migrates to cut edges autonomously [NEED_CITE: ZAM coating self-healing mechanism at cut edges]. For curtain wall contractors, this means no touch-up painting after field cutting — a detail that saves weeks of scaffolding rental on high-rise projects.
Matching ZAM-Coated Tubes to Architectural and Structural Demands
The zero spangle finish on this ZAM coated galvanized square rectangular steel tube delivers a uniform matte surface that accepts powder coating directly without additional primer treatment — critical for exposed facade members where visual consistency matters. Our patented sharp-corner rectangular tube technology produces true right-angle corners rather than the rounded radii typical of standard RHS, allowing flush connections at curtain wall mullion intersections. Wall thickness coverage from 0.5mm light gauge for cladding supports up to 30mm for primary structural columns means a single supplier can fulfill both secondary and primary steel packages on the same project.
Engineering Compliance and Certification Requirements
Structural hollow sections for load-bearing applications must conform to dimensional tolerances specified in EN 10219 for cold-formed welded structural hollow sections, and our ±1% tolerance range meets these requirements across the full 20×60mm to 40×75mm size spectrum [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerances]. For EU market projects, CE certification under EN 10210/10219 is mandatory for structural steel imports — our mill holds Lloyd’s CE certification covering these product standards. Steel grade selection between Q195, Q235, and Q355 directly affects load-bearing capacity; Q355 provides higher yield strength for primary structural members while Q195 suffices for non-load-bearing facade supports. Custom cut-to-length service at 5.8m, 6m, 6.4m, or 12m reduces on-site waste and welding joints.
Steel Grade Selection and ERW Welding Process
Q195, Q235, and Q355 represent the Chinese GB standard carbon structural steel series where the number indicates minimum yield strength in MPa — Q355 delivers approximately 50% higher yield capacity than Q195, making it suitable for primary structural frames while Q195 serves light-duty applications like scaffolding and cladding supports. The ERW (Electric Resistance Welded) manufacturing process creates a longitudinal weld seam by passing high-frequency current through the steel strip edges, producing a clean internal bead suitable for fluid conveyance and structural use. ZAM coating application follows forming and welding, depositing a zinc-aluminum-magnesium alloy layer with 55% aluminium content that provides superior corrosion resistance compared to pure zinc galvanizing. The zero spangle surface treatment eliminates the characteristic crystalline pattern of standard galvanized coatings, producing a smooth uniform appearance preferred for architectural applications.
Hidden Costs of Incorrect Material Specification
Specifying Q195 when structural calculations require Q355 creates immediate safety liability — the lower yield strength cannot support design loads, forcing complete member replacement after installation. Missing CE documentation blocks customs clearance at EU ports, triggering demurrage charges and project delays that far exceed the material cost difference [NEED_CITE: customs clearance requirements for structural steel imports to EU]. Undersized wall thickness from negative tolerance abuse reduces load capacity below engineering specifications, creating structural failure risk during service. These errors compound when discovered after shipment — return logistics and replacement production schedules disrupt entire project timelines.
Manufacturing Capability and Quality Assurance
Our three dedicated ERW production lines cover over 2,800 specification combinations including the full range of ZAM coated square and rectangular tubes from 20×60mm light gauge to heavy structural sections with walls up to 30mm. The in-house physical and chemical laboratory performs coating thickness verification, dimensional inspection, and mechanical testing on every production batch before release. We hold 41 invention patents including China’s original sharp-corner rectangular tube technology that produces true right-angle corners for architectural applications — this patented process fills a gap in the domestic and international market for facade-grade structural tubes. Full certification package includes ISO 9001:2015 quality management, Lloyd’s CE marking for EN 10210/10219 compliance, Singapore FPC certification, and third-party verification through SGS and BV. Professional container loading protocols with anti-damage measures prevent coating abrasion and tube deformation during ocean transit to 50+ export destinations.
Documentation & Compliance
- Mill Test Certificate documenting Q195/Q235/Q355 chemical composition and mechanical properties per GB standard with heat number traceability
- CE Certificate (EN 10210/EN 10219) issued by Lloyd’s Register covering ZAM coated structural hollow sections for EU market compliance
- ISO 9001:2015 Quality Management System certificate covering ERW tube manufacturing and ZAM coating processes
- SGS or BV third-party inspection report verifying coating thickness (AZ61–AZ80), dimensional tolerance (±1%), and surface quality before shipment
- Material traceability documentation linking each bundle to specific heat numbers and production batch records
- Complete customs documentation including packing list, bill of lading, and certificate of origin for import clearance
Packaging, Loading & Delivery
- ZAM coated tubes bundled with steel strips and edge protectors to preserve the zinc-aluminum-magnesium coating during ocean transit and prevent coating abrasion
- Zero spangle surface protected with anti-fingerprint film or interleaving paper for architectural applications requiring pristine finish quality
- Custom length cutting at 5.8m, 6m, 6.4m, or 12m optimizes container loading efficiency and reduces on-site cutting waste for facade projects
- Plastic end caps installed on all tube ends to prevent moisture ingress and coating damage at cut edges during storage and transport
- Heat number and steel grade markings stenciled on each bundle for site identification and quality traceability verification
- FOB/CIF/DDP shipping terms available with professional container loading supervision to maximize payload while preventing transit damage
Initiating Your Procurement Process
Submit your specification requirements including section dimensions, wall thickness, steel grade (Q195/Q235/Q355), coating grade preference (AZ61–AZ80), quantity, and destination port to receive a detailed quotation with unit pricing, production lead time, and shipping terms within 12 hours. For non-standard sizes outside our 2,800+ specification range, our engineering team provides custom manufacturing solutions with low minimum order quantities. We arrange third-party inspection (SGS/BV) and provide complete mill test certificates and CE documentation for your import clearance requirements.
Frequently Asked Questions
Q: What is ZAM coating and how does it compare to standard hot-dip galvanized?
A: ZAM (Zinc-Aluminum-Magnesium) coating contains 55% aluminium and magnesium additions that create a denser corrosion product layer compared to pure zinc galvanizing. The magnesium content enables self-healing at cut edges, where the coating migrates to exposed steel surfaces and forms protective zinc hydroxide, providing 3–5 times better corrosion resistance in harsh environments.
Q: Can you produce custom non-standard sizes with low MOQ?
A: Yes, our three production lines cover over 2,800 specification combinations, and we manufacture custom non-standard sizes beyond our standard range including 20×60mm and 40×75mm. Custom sizes enter production with typical lead times of 15–25 days, and we accommodate low minimum order quantities for project-specific requirements.
Q: What is the difference between sharp-corner rectangular tube and standard RHS?
A: Standard rectangular hollow sections have rounded corners with radius typically R≥2t (twice the wall thickness), while our patented sharp-corner technology produces true right-angle (90-degree) corners. This eliminates the unfinished appearance at connection points and provides superior aesthetics for glass curtain walls and architectural facades.
Q: Do you provide CE certification for EU market imports?
A: Yes, our mill holds Lloyd’s CE certification covering EN 10210 (hot-finished structural hollow sections) and EN 10219 (cold-formed welded structural hollow sections). This certification is mandatory for structural steel imports into EU member states and ensures compliance with European construction product regulations.
Q: What is the production lead time for custom sizes versus stock items?
A: Standard sizes from our regular production range ship from stock with immediate availability. Custom non-standard sizes or specific coating grade requirements (AZ61–AZ80) enter production with typical lead times of 15–25 days depending on order complexity and quantity.
Request Your ZAM Tube Quotation
Send your project specifications including dimensions, steel grade, coating requirements, and destination to receive pricing and mill test certificates within 12 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
