What does AFS40-45 mean in chromite sand casting materials?
The American Foundry Society (AFS) stipulates that “fineness” is one of the parameters that reflects the characteristics of foundry sand. It has been for at least 50 years and is called “AFS fineness.”
Calculation method of AFS fineness: The measurement steps and calculation method of AFS fineness specified by the American Foundry Association are as follows:
1. First weigh about 50g of the sand sample to be measured, wash off the mud, dry it, and then sift it;
2. Weigh and record the mass of sand particles remaining on each sieve;
3． Calculate the percentage of sand particles remaining on each sieve to the total amount of sand sample;
4. Multiply the percentage of sand particles remaining on each screen by the “AFS fineness multiplier” corresponding to each screen;
5. Add the products found above for each sieve number to find the total:
6. Divide the sum obtained in item 5 by the sum of the percentages of sand remaining on each screen in item 3 to obtain the AFS fineness. “AFS fineness multiplier” corresponding to each screen number
Then average the values to get the average fineness.