For any designer or contractor who uses HDG steel, knowing the Time to First Maintenance of their steel article is critical as it helps them decide the feasibility of the project.
What is Time to First Maintenance?
Time to First Maintenance is the estimated time it takes for the base steel surface to lose 5 percent of its galvanized coating. This means, the steel will have to be repaired so that it can continue to perform the same way it did originally.
It’s important to note that Time to First Maintenance does not equal to the service life of the HDG steel article; 95 percent of the steel surface is still covered with thegalvanized coating.
So, how do you estimate the Time to First Maintenance of a HDG steel article?
The Time to First Maintenance of a HDG steel article can be estimated using the Time to First Maintenance (TFM) Chart. This chart is developed by the American Galvanizers Association, a not-for-profit organization dedicated to helping architects, contractors, engineers, fabricators and specifiers with everything galvanized steel.
The chart is basically a graph. On the x-axis, you’ve the average thickness of the zinc coating in mils, and on the y-axis is the Time to First Maintenance in years. It features five distinct plotlines, each representing specific climate types.
To use the TFM Chart, you must know the thickness of the galvanized coating and the type of climate in which the structure is to be deployed. Once you know these two parameters, you can then use the chart like any normal graph and estimate the Time to First Maintenance of a steel article. It’s worth mentioning here that the chart is not applicable for estimating the Time to First Maintenance of a steel article to be submerged in water or soil.
How does the TFM Chart itself compute the results?
The TFM Chart uses the information from the Zinc Coating Life Predictor, an online tool designed by Dr. X. G. Zhang. You can access the tool here.
Do you have any other questions about using HDG steel for construction or product fabrication? Feel free to reach out; our HDG steel experts will be happy to help you.
We also manufacture and supply high quality hot-dipped galvanized steel coils in bulk. If you’re looking to source high quality HDG steel for your project, we can deliver it to you right at your doorstep.
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