Hot dip galvanizing of the strip is carried out by immersing it in a zinc bath maintained at 460 degree centigrade. The chemistry of the bath is carefully controlled to ensure proper adhesion and formability of the applied zinc together with bright blemish free uniform spangles.
The galvanized coils are chromated to improve its resistance to white rust. The chromating parameters are continually monitored and sheets are regularly tested through salt-spray tests to ensure the performance of this process.
material is produced on continuous hot dip galvanizing lines by passing prepared coils through a bath of molten zinc. There are various styles available Minimized Spangle, Minimized Spangle - Extra Smooth. The zinc coatings on these products help resist corrosion due to the barrier protection and sacrificial characteristics of the coating. The required zinc coating thickness for different coating specifications is achieved as the result of passing the hot dipped strip through a variable low pressure, high volume air stream, called an "air knife."
The coating consists of a layer of zinc on top of a very thin layer of a mixture of intermetallic compounds containing iron, aluminium and zinc. The products produced are almost "spangle" free. The surface has a bright appearance and is normally intended for plain unpainted construction applications or unexposed appliance/ automotive applications.
This product is skin passed or temper rolled after coating to impart a uniform matte surface appearance. It is developed for use on painted construction applications and semi-exposed automotive applications requiring an improved surface appearance.
Air conditioning equipment, HVAC ductwork, wood connectors, slot machine parts, computer cabinets, TV cable boxes, building panels, display cases, electronic equipment, garbage cans, guide rails, heating equipment, highway culverts, garage doors, motor housings, washing machines and dryers, home appliances, lighting fixtures, mailboxes, outdoor signs, refrigerators and freezers, roof flashing, decking, tool boxes, vending machines, framing studs, rain gutters and downspouts.
Lends itself to most fabrication processes; it can be roll-formed, brake-formed, lock-seamed, deep drawn, and stretched. It can be joined by various methods including adhesive bonding, riveting, soldering and welding.
Galvanized sheet metal can be readily painted before or after fabrication when the proper pre treatment is performed.
|(Material in <0.80 mm thickness can also be supplied hard temper)|
|0.10-0.25 mm||: +15 microns (spread of 30 microns)|
|>0.25-0.50 mm||: +20 microns (spread of 40 microns)|
|>0.50-1.0 mm||: +30 microns (spread of 60 microns)|
|>1.0 mm thickness||: +2.5 % of thickness or 100 microns|
|(whichever is higher)|
|Full width||: 760 – 1250 mm|
|Full width tolerance||: +5/-0 mm|
|Slit width||: 50-1240 mm|
|Slit width tolerance||: +0.50/-0.50 mm (spread of 1.0 mm)|
|Length tolerance||: 500 – 4000 mm|
|Standard sheets||: +10/-0 mm (spread of 10 mm)|
|Blanks||: +1 mm (spread of 2 mm)|
|Coating||: 90 – 275 gsm|
|Edge Condition||: Trimmed / mill edge|
|Edge condition tolerance|
|Edge wavy coils||: 4 mm, 3 waves / meter|
|Edge wavy sheets||: 5 mm, 2 waves / meter|
|Edge Camber||: 2 mm max. In 2 mtr length|
|Buckling||: 5 mm 2 nos. Per meter|
|Bow||: 10 mm max|
|Diagonal difference||: 5 mm max|
|Temper – 1||: Soft / Hard|
|Temper – 2||: Stretch levelled / non stretch levelled / skin passed|
|Stretch levelling||: 0.23 – 2.50 mm thickness|
|Skin passed||: 0.30 – 2.50 mm thickness (soft only)|
|Surface roughness||: 0.60 – 2.0 microns ( after skin passed )|
|Surface finish||: Bright / matte (regular/small/big/suppressed spangles)|
|Surface treatment||: Chromated / im-chromated & oiled|
|Oiling||: 100 mg/m2 to 1000 mg/m2 each side|
|Monogram||: Online logo can be given|
|Coil ID||: 508 mm|