BS EN ISO 3506-4:2025

Fasteners. Mechanical properties of corrosion-resistant stainless steel fasteners. Tapping screws with specified grades and hardness classes | Status: Current

1 Scope This document specifies the mechanical and physical properties of tapping screws made of corrosion resistant austenitic, martensitic, ferritic and duplex stainless steels, with specified grades and hardness classes. ISO 3506‑6 provides general rules and additional technical information on suitable stainless steels and their properties (detailed properties of stainless steel grades, corrosion behaviour with regards to pitting, crevice and intergranular corrosion, magnetic properties, etc.).

WARNING Tapping screws conforming to the requirements of this document are tested at the ambient temperature range of 10 °C to 35 °C and are used in applications ranging from –20 °C to +150 °C. It is possible that they do not retain the specified mechanical and physical properties at lower and/or elevated temperatures. Therefore, it is the responsibility of the user to determine the appropriate choices based on service environment conditions of the assembly (see also Clauses 5 and 6).

This document applies to tapping screws with threads ST2,2 to ST8, in accordance with ISO 1478. This document does not apply to tapping screws with special properties, such as weldability.