ASTM stands for American Society for Testing and Materials. It is a non-profit society based in West Conshohocken, Pennsylvania. Its history spans back to 1898, when Charles Benjamin Dudley formed a society to address frequent rail-breaks. This group published standard setting requirements for steel that was used to construct rails.
Unlike other standardization bodies, such as DIN or ANSI, ASTM is not a national standards body, however it has gained its dominant role in the field of standardization in USA.
Currently there are about 12000 valid standards.