ZAM — zinc-aluminium-magnesium coated steel — is sold under producer brand names. Buyers and specifications often use the brand as if it were the product.
| Brand | Producer | What it is |
|---|---|---|
| Magnelis | AM/NS India (ArcelorMittal) | Zn-Al-Mg metallic coating |
| PosMAC | POSCO | Zn-Mg-Al metallic coating |
| Magsure | JSW Steel | Zn-Al-Mg metallic coating |
| ZAM | Tata Steel, Dongkuk | Zn-Al-Mg coated steel |
The same idea, not the same product
All of these add magnesium and aluminium to a zinc coating, which typically improves corrosion resistance — especially at cut edges and punched holes — compared with conventional galvanizing of similar coating mass. But the exact chemistry, the coating classes offered, and each producer's test data differ.
When a switch needs approval
- A solar-structure or cable-tray design certified on one brand's test data
- A specification that names the brand or its coating class
- Corrosion-life warranties given by an EPC or developer
In these cases, treat a change of brand as a substitution and get it approved. Where the specification simply calls for ZAM to IS 18513 with a stated coating mass and substrate grade, suppliers can be compared on that basis.
What to put in the enquiry
Brand (if specified), coating designation, substrate yield strength, thickness, slit width or sheet size, and quantity.
Related: ZAM coils · ZAM sheets · IS 18513 · GP vs GL vs ZAM