ISO 3506-4 specifies the mechanical properties of tapping screws made from austenitic, martensitic and ferritic grades of corrosion-resistant stainless steels when tested at an ambient temperature range of 15 °C to 25 °C. Properties vary between higher and lower temperatures. It applies to tapping screws with threads from ST2,2 up to and including ST8 in accordance with ISO 1478. It does not apply to screws with special properties such as weldability. ISO 3506-4 does not define corrosion or oxidation resistance in particular environments, however some information on materials for particular environments is given in an annex. The aim of ISO 3506-4 is a classification into property classes of corrosion resistant stainless steel fasteners.