Trade Number

Trade number is a combination of letters and a number used by cutting bur manufacturers for describing the size and shape of a bur. The letters designate the shape, and the number refers to the size. For example, an SM-1 bur is Shape M, cone shaped, has a 1/2" cut length, and has a 1/4" head diameter. Trade number is defined by the International Organization for Standardization (ISO) 7755, which standardizes the names and sizes of cutting burs.