M&M grating is a type of grating. I don't think it is used much now. The company "Fisher and Ludlow" used to carry it but they don't anymore and they no longer have their load tables for it.
I will be reusing an existing M & M grating and I cannot find any load tables to determine its' capacity. I also don't know its' yeild stress. Any information on M & M gratings would be greatly appreciated. Thanks