A cosmetic applicator or assembly part for a cosmetic applicator, includes a thread spindle drive for moving a cosmetic mass lead relative to a lead housing tube accommodating the lead, wherein a thread is formed on an inner peripheral surface of the lead housing tube, and the thread interacts with a complementary thread of a lead holder, and the thread moves the lead holder together with the lead relative to the lead housing tube translationally when the lead holder is rotated, wherein said thread of the lead housing tube is not a continuous thread, but consists of a plurality of thread islands that are spaced apart from each other, each of the plurality of thread islands having thread projections extending by less than 121 in a circumferential direction and being shaped and arranged such that an outer thread of the lead holder always engages with at least one thread island.