Regular spangle Galvalume coil carries a visible crystalline surface over a 55% aluminium, 43.4% zinc and 1.6% silicon coating. BOMIS supplies it chromated and oiled, from AZ30 to AZ200 g/m², 600 to 1250 mm wide, with the mill certificate on every coil.
Spangle is what the coating looks like as it freezes, and regular spangle is the finish that shows it. Corrosion performance does not change with spangle at the same coating weight, so the choice comes down to appearance and to whether the coil will be painted later.
Chromating protects the surface, so the coil survives storage and shipping without white rust. The oil film then keeps the wraps from marking each other under tension and helps the strip run clean through a roll former. Together they buy time: coils can sit in a warehouse for months before forming. An oiled coil also unwinds more evenly on the slitting line. Where the formed part stays visible, the spangle reads as texture rather than defect.
| वस्तु | मूल्य |
|---|---|
| Coating composition | 55% Al, 43.4% Zn, 1.6% Si |
| AZ coating weight | 30 – 200 g/m² |
| मोटाई | 0.12 – 1.2 mm |
| चौड़ाई | 600 – 1250 mm |
| Size tolerance | ±1% / ±3% / ±5% / ±7% |
| Spangle | Regular |
| सतही उपचार | Chromated and oiled |
| Certificates | MTC, ISO 9001, SGS |
| न्यूनतम मात्रा | 16 metric tons per specification |
This finish goes wherever a coil sits before it is used, which covers most construction work and much of agriculture. The oil helps the strip run through a roll former without marking, so profiled sheet and composite panels are the two biggest outlets.
Coils run chromated and oiled on our own galvanising line, so the passivation is applied before the coil is wound rather than after. We slit to press width or cut to sheet size in house. Tell us at enquiry stage whether the coil will be painted later, because that decides whether you want chromate, oil, or both. Lead time runs about three weeks for standard specifications.
Coils ship with the mill certificate and edge protectors on both ends. Standard sea packing is waterproof kraft paper under a galvanised steel jacket, steel strapped, which holds through a forty day crossing without edge rust. Eye to the sky or eye to the wall, your call.
Choose regular spangle when the bare surface will be seen. Choose minimised spangle when the coil goes for painting, because a smoother surface takes a more even coating.
Not directly. Chromate and oil both have to be removed or overcoated with the right pretreatment before painting, and we confirm which route with your paint supplier.
Chromated and oiled coils hold for several months in a dry warehouse. Keep them off the ground and avoid condensation, which is what causes white rust at the edges.
Yes. Every coil leaves with its mill test certificate, and we confirm which document you need before production starts.
16 metric tons per specification, and about three weeks for standard specifications.
Yes. The same substrate runs through our colour coating line, so roofing in particular usually ships as prepainted rather than bare.
