Self-tapping fastener

A self-tapping fastener made of stainless steel having a shaft with a tool access at its one end and with a boring part at its other end with optionally a thread on a partial section, characterized in that the shaft is formed of two sections (7, 8) of stainless material, which are connected to each other by positive, material and/or frictional engagement, wherein the first section 7 of shaft 2 which has the tool access (4) and optionally a threaded region, is made of stainless, purely ferritic or austenitic steel or stainless compound steel and a second section (8) of shaft (2) which is configured as boring part (5) or includes the boring part (5) is made of a martensitic stainless steel with a carbon content of 0.04% to 0.3%.