What does galvanized sheet G30 G40 G60 G90 mean?

It turns out that the domestic method of expressing the zinc layer thickness of galvanized sheets is directly Z40g Z60g Z80g Z90g Z120g Z180g Z275g. (The amount of galvanizing is a commonly used and effective method to express the thickness of the zinc layer of galvanized sheets.)

Domestic standard value of galvanizing amount: The unit of galvanizing amount is g/m2.

Foreign countries like to use G30 G40 G60 G90 to express the amount of zinc. The conversion relationship between them is:

1oz=0.0284kg, so 0.9oz=0. 02556kg=25.56g 1ft2=0.093m2 25.56g/0.093m2=275g/m2.

For Example

G90 means that the average minimum weight of the galvanized sheet measured at three points on both sides is 0.9oz/ft2, that is, the SI unit is 275g/m2.

Simply put, galvanized sheet G60 is what we usually call Z180g zinc layer galvanized sheet.

The Steel Code has prepared a convenient zinc layer comparison table for you. When you meet foreign customers in the future, you will know how much zinc layer is required when they ask about G60!

ASTM Standards:

Further Reading:

In China, some customers like to use the unit of microns to calculate the thickness of the zinc layer. Here is the analysis for you.

The density of zinc is 7.14 grams/cm3; so 275/7.14=38.5154cm3=38515.4mm3, that is, the average thickness per square meter is 38.5154 microns. (Single-sided) Double-sided is half that.

The weight of 1 micron zinc plated per 1m2 is 7.1g, 275g/7.1>31 micron (average thickness). If a thickness gauge is used for acceptance, the average thickness measured may be higher than 31 microns, because the roughness of the steel surface and the roughness of the coating will affect the test results. The greater the roughness, the greater the measured thickness.

Hot-dip galvanizing layer thickness standard, How thick is the galvanized layer? 

Electro galvanizing thickness standard

Highlight!!!

First remember that 7.14 is the density of zinc! No matter how many grams per square meter the other party says, Just use this number + 7.14. The result is the thickness per square meter in microns.

1. For example, you said that the amount of zinc per square meter is 80 grams. How thick is it?

80+7.14-11.2 (micronμm)

2. Some people may ask for a zinc content of 70 microns. How many grams per square meter is that?

70*7.14=499.8g/m²