ZAM steel cable trunking is fabricated from sheet steel coated with a zinc–aluminium–magnesium (Zn–Al–Mg) alloy. The coating is developed to improve corrosion resistance and to help protect cut edges more effectively than some common galvanized steels when used in suitable conditions.
It is considered for factories, solar systems, technical infrastructure and projects that need a balance of corrosion protection, structural weight and fabrication lead time. Actual performance depends on material grade, coating composition and mass, environment, cable-route design and project acceptance requirements.
At The Sun, ZAM steel cable trunking is fabricated to required dimensions, thickness, construction and drawings, together with covers, couplers and accessories. Read our detailed article on ZAM steel for cable support systems.
1. What is ZAM steel cable trunking?
ZAM steel cable trunking is made from steel sheet coated with a Zn–Al–Mg alloy before fabrication. Blanks are cut, punched and folded into trunking bodies, covers and direction-changing accessories. Trade names, alloy composition and coating mass can vary by manufacturer; verify the material certificate rather than relying on the name “ZAM” alone.
It is normally a closed-box trunking system and may use a cover to limit dust and mechanical impact from above. A complete system includes straight lengths, covers, couplers, horizontal and vertical bends, tees, crosses, reducers and support assemblies.
2. How does the Zn–Al–Mg coating protect steel?
The alloy coating forms a barrier between base steel and the environment. Zinc provides electrochemical protection, while aluminium and magnesium help form more stable corrosion products on the surface in suitable conditions.
At a cut edge, corrosion products from adjacent coating can form and partly cover exposed base steel, slowing corrosion. This is often called “cut-edge protection”; it does not mean every cut can fully self-heal or remain corrosion-free.
3. When should ZAM steel cable trunking be considered?
- Factories and industrial zones: indoor, semi-outdoor or humidity-exposed routes requiring evaluation.
- Solar systems: projects needing corrosion resistance with practical structural weight.
- Technical infrastructure: routes with many punched holes, cut edges and coordinated accessories.
- Data centres: where it meets MEP design, load, earthing and material requirements.
- Fast fabrication projects: pre-coated sheet avoids hot-dip galvanizing after forming.
For marine exposure, strong chemicals, immersed areas or strict hygiene requirements, assess the actual corrosion class and technical data for the exact material. ZAM should not automatically be assumed suitable for every outdoor environment.
4. Benefits and limitations
Benefits
- Good corrosion resistance in suitable environments.
- May protect cut edges better than some conventional galvanized sheet products.
- Can be cut, punched and folded directly from pre-coated sheet.
- No post-fabrication hot-dip galvanizing process is required.
- Uniform metallic surface without a paint-colour selection requirement.
Limitations
- Not all Zn–Al–Mg steels have the same composition or performance.
- Large cuts, deep grinding or widespread damage may require extra protection.
- Corrosion resistance depends strongly on chlorides, chemicals, standing water and time of wetness.
- Material availability, price and lead time vary by grade and supplier.
5. Construction and accessory system
- Trunking body: contains and protects cable routes.
- Cover: used as required for shielding and maintenance.
- Couplers: connect straight lengths into continuous routes.
- Accessories: horizontal bends, up/down bends, tees, crosses and reducers.
- Support system: brackets, strut channels, threaded rods and load-rated fixings.
Accessories should use compatible materials and construction. Drawings should confirm orientation, hole positions and joint type to minimise on-site cutting.
6. Reference specifications
| Parameter | Reference specification |
|---|---|
| Product | ZAM / Zn–Al–Mg steel cable trunking |
| Form | Closed trunking, with optional cover |
| Base material | Zn–Al–Mg alloy-coated steel sheet |
| Coating grade | According to material certificate and project requirement |
| Length | According to manufacturing and transport limits |
| Width W / height H | According to cable-route design |
| Thickness T | According to size, load and support spacing |
| Accessories | Bends, tees, crosses, reducers, couplers and supports |
| Fabrication | To standard dimensions or drawings |
Common sizes
100 × 50, 200 × 50, 100 × 100, 200 × 100, 300 × 100 and 400 × 100 mm are common. The Sun can fabricate other sizes to drawings. Select size from cable quantity and diameter, bend radius, fill ratio, expansion allowance and installation space.
7. Selecting trunking thickness and support spacing
Do not reduce thickness merely because the material has a corrosion-resistant coating. Load capacity depends on base steel, section shape, trunking width, total cable weight, support spacing and installation orientation.
- Trunking W × H dimensions.
- Cable load per metre.
- Support spacing and type.
- Horizontal, vertical and direction-changing runs.
- Installation load and future cable additions.
- Transport, lifting and installation conditions.
8. What to check on the material certificate
- Material trade name and manufacturer.
- Zn–Al–Mg coating composition or type.
- Coating mass or grade.
- Base-steel thickness and tolerance.
- Steel mechanical properties where required.
- Test standards and batch traceability records.
Do not state a fixed aluminium or magnesium ratio for every ZAM product. Coating composition is product-specific and must be confirmed in the manufacturer or supplier documentation.
9. ZAM steel cable trunking production process
Material inspection → blank cutting → punching/cutting to dimensions → folding → accessory fabrication → assembly inspection → cleaning → packing.
Because the sheet is pre-coated, fabrication should minimise scratches, deep grinding and surface contamination. Holes, slots and accessories should be finished in the factory to reduce site work.
10. Product quality checks
- Dimensions: width, height, length, thickness and hole positions.
- Form: straightness, squareness and distortion after folding.
- Fit-up: cover closure, straight-length coupling and accessory fit.
- Surface: scratches, burrs, sharp edges and irregularities.
- Material: comparison with required grade and certificate.
11. Transport, storage and installation
- Store dry and ventilated; avoid standing water between product layers.
- Do not drag trunking on hard surfaces or allow impacts that deform it.
- Remove burrs and sharp edges before cable installation.
- Consider extra protection at large cut or ground areas.
- Provide equipotential bonding and earthing to the electrical design.
- Do not indiscriminately combine dissimilar metals where galvanic corrosion is possible.
12. Comparison with other cable-trunking materials
| Material | Main feature | Common environment considered |
|---|---|---|
| ZAM / Zn–Al–Mg | Alloy coating; helps protect cut edges | Factories, solar, infrastructure; dependent on corrosion class |
| Pre-galvanized steel | Easy fabrication and economical | Indoor, relatively dry |
| Powder-coated steel | Many colours and finished appearance | Indoor, colour or aesthetics required |
| Hot-dip galvanized steel | Coated after fabrication | Outdoor or humid areas; environment must be assessed |
| Stainless steel 304/316 | High corrosion resistance and cleanability | Food, chemical and demanding environments |
No material is best for every project. Select from corrosion class, design life, load, fabrication method, supply availability and total lifecycle cost.
See also Cable Trunking, Pre-Galvanized Cable Trunking and Hot-Dip Galvanized Cable Trunking.
13. ZAM steel cable trunking quotation
Price depends on material grade, thickness, W × H dimensions, length, quantity, construction, accessories, certificates and delivery location. Material supply and minimum order quantity can also affect price and lead time.
For an accurate quotation, provide material grade + dimensions + thickness + quantity + accessories + documentation requirements + drawing (if available).
14. The Sun fabricates to project drawings
The Sun manufactures trunking bodies, covers, couplers and accessories to standard dimensions or drawings. Material, hole positions, joint construction, accessories and quality documentation should be agreed before production.
15. Frequently asked questions
Is ZAM a generic name for all Zn–Al–Mg steel?
Not entirely. ZAM may be used as a trade name or a familiar term. Composition, coating mass and performance data must be verified for the specific product and supplier.
Does ZAM coating heal every cut?
No. Coating corrosion products can help cover and slow corrosion at a cut edge in suitable conditions. Large cuts or deep damage may still need additional treatment.
Can ZAM cable trunking be used near the sea?
Assess chloride concentration, distance from the sea, time of wetness, coating grade and design life. Do not decide solely from the material name.
Is ZAM lighter than hot-dip galvanized steel?
Weight depends on steel thickness and section design. It cannot be declared lighter without comparing configurations with equal load and stiffness requirements.
What is needed when ordering?
Provide material grade, dimensions, thickness, length, quantity, accessories, installation environment, documentation requirements and drawings if available.
16. Order ZAM steel cable trunking
Send the cable-route information or drawings to The Sun so we can check dimensions, material grade, accessories, availability and quote for your project.
THE SUN JOINT STOCK COMPANY
Website: thesun.vn
Hotline/Zalo: 0903 988 018
Email: info@thesun.vn
Products: Cable trunking, cable trays, cable ladders, wire mesh trays and accessories.