A thread-tapping screw has a shaft (12) with first (13) and second (14) ends, a load application element (15) provided at one of the first and second ends (13, 14), a thread (16) extending at least regionwise along the shaft (12), and at least one wear indication element (21, 26, 31; 36, 41; 51, 56; 61, 66) provided on the thread (16).