Designation system is given in terms such as g60 g90 etc.
G90 galvanized sheet metal weight.
If equally applied to both sides of the sheet there would be a minimum of 0 45 ounces on each surface.
Hot dip galvanizing is the process of coating iron or steel with a thin zinc layer by passing the steel through a molten bath of zinc at a temperature of around 860 f 460 c.
Batch galvanizing coating specifications are given in weight per surface area.
24 gauge 20 gauge 18 gauge and 16 gauge.
Cold and hot rolled steel.
26 gauge 24 gauge 20 gauge 18 gauge 16 gauge 14 gauge 1 8 and 1 4.
When exposed to the atmosphere pure zinc reacts with oxygen to form zinc oxide which further reacts with carbon dioxide to form zinc carbonate a dull grey fairly strong material that stops further.
The standard product is class g90 which has 0 9 oz ft 2 of sheet total both sides or about 0 76 mils 18 µm thickness per side.
48 oz 24 oz 20 oz and 16 oz.
These numbers refer to the weight mass in si units of zinc on the surface of the steel sheet in inch pound english or imperial units of measurement.
Taking g90 as an example the coating weight on one square foot of sheet total both sides of the sheet shall have a triple spot test tst average minimum of 0 90 ounces.
16 gauge 14 gauge 1 8 and 1 4.
The galvanized sheet coating parameters relate to the total for both sides of the sheet.