Flat form A washers are the most common type of washer used today. Primarily the stamped version to Din 125 A is supplied due to the availability and the economical price compared to the BS4320 version which have more of a machined flat finish.
Form A is a thicker version of the Form B with the same outside and internal dimensions.
For a larger diameter to the flat form A washers opt for form C, form D, form F or form G.