A method for stretch breaking fibers to produce a staple yarn and operating a staple fiber spinning machine that enables the production of a plurality of products of lot size smaller than a large denier tow product. The process includes at least two break zones and a consolidation zone downstream from a second break zone to form a staple yarn. The filaments are broken in a second break zone downstream from the first break zone by increasing the speed of the fiber fed into the process. The yarn includes discontinuous and, optionally, continuous filaments.