ISO 3506-3:2025

Fasteners — Mechanical properties of corrosion resistant stainless steel fasteners — Part 3: Set screws (and similar fasteners not under tensile stress) with specified grades and hardness classes

Scope

This document specifies the mechanical and physical properties of set screws and similar fasteners not under tensile stress, made of corrosion resistant austenitic 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 — Set 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 application 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 set screws and similar fasteners not under tensile stress
—     with ISO metric thread in accordance with ISO 68-1,
—     with diameter/pitch combinations in accordance with ISO 261 and ISO 262,
—     with nominal thread diameter 1,6 mm to 24 mm,
—     with thread tolerances in accordance with ISO 965-1 and ISO 965-2,
—     with specified hardness classes, and
—     of any shape.
NOTE            The term set screw is used in the following for all screws and similar fasteners not under tensile stress within the scope of this document.
This document does not apply to screws under tensile stress (see ISO 3506-1). It does not specify requirements for functional properties such as shear strength or weldability.