Do you know the basic knowledge of coating steel?

Many clients have been dealing with coating steel such as galvanized steel (GI), galvalume steel (GL), aluminized steel (AS), zinc aluminum magnesium coated steel (ZAM) for many years even dozens of years, but do you really know the difference between various coating mass, especially the price gap?

Take galvanized steel which people use most widely as the example. Normally the zinc coating is between Z40 and Z275, quite few suppliers can make it up to Z500-600 like MESCO. With the coating goes from low to high, its anti corrosion ability becomes stronger. For instance Z40 can last 3~5 years without rust while Z275 can last 30 years. But surely Z40 and Z275 have totally different prices as we know. Some dishonest suppliers may quote with the price of low zinc coating but say it’s for high zinc coating. Actually this kind of tricks in most cases are played by 3 ways. First, directly use the price of Z40 to replace that of any other higher coating, Z180 Z220 Z275 etc. There is absolutely no technique with this kind. One time cooperation, max two times will be kissed goodbye because it’s not difficult to be found out. Second, use medium zinc coating like Z80 Z120 to replace Z180 Z275, this kind of suppliers have a little conscience, but they are rare as well. Third, make a few meters of the beginning and the end of one coil with enough Z275, but mostly of it is Z40. This kind is the most difficult to find out because when people do the test, they usually cut sheets from those two parts, not the middle of the coil.

Besides, you can check the surface of samples to know whether it is high zinc coating. For regular spangle GI, Z275 has very clear and beautiful spangle. And we advise you to buy a coating thickness gauge, which will easily tell the zinc mass.

Then how do we distinguish whether the price of high zinc coating is true? The most direct and effective way is to calculate. Considering the calculating progress is a bit complicated, here we just tell the general price difference of every 20 gram/m2 of zinc coating, 0.5mm-20 USD. The thinner it is, the bigger the price gap is. So, 0.2mm thickness with Z275 is not possible, because for one hand the sheet is too thin to hold so much zinc on it and for the other hand the theoretical price will be extremely high. Now let’s take 0.8mm as an example, if the price of Z40 is 800 USD, then Z275 is about 944 USD. Of course, the price gap changes along with the zinc price goes up and down, but the range may not be big.

There is another simple way for this, ask MESCO directly. We truly hope that we’ll have the chance to build a close business relationship with you, but if we can’t in the short term, we also won’t lie to you, it is promised. You can trust us any time with full heart.

MESCO is waiting for your contact with all of our enthusiasm!