The current standard requirements for glazes include resistance to scratching by glass and steel and a Mohs hardness above 5. The current requirement for wear factor (index) is at or below 15. The Federal Standard Test (FST) No.141 is defunct. As such, reference must be made to a new standard. It is believed that ASTM Standard D4060 most closely replaces FST 141 and should be referenced. However, data on stone flooring indicates that Mohs hardness can be correlated to wear index and that a Mohs above 5 would relate to a wear factor (index) of approximately 7. (Reference: Porosity and Wear Resistance in Stone Flooring Tiles) Thus, in solely retaining the Mohs hardness requirement, the user can have confidence that glazes meeting this requirement would have also meet wear index.
Keywordsbrick; ceramic glaze; clay; glaze properties; masonry; physical properties; shale; tile;
Ballot Item Approved as C126-2015 and Pending Publication