EN ISO 3506-5:2023

Overview - EN ISO 3506-5:2023 (ISO 3506-5:2022)

EN ISO 3506-5:2023 specifies the mechanical and physical properties of corrosion-resistant stainless steel and nickel-alloy fasteners intended for high temperature applications (up to 800 °C). It covers bolts, screws, studs and nuts with both coarse-pitch and fine-pitch threads, focusing on special fasteners made from martensitic stainless steels, precipitation‑hardening austenitic stainless steels and nickel alloys. The EN adoption (2023) implements ISO 3506-5:2022 across CEN member countries.

Key topics and technical requirements

• Materials and manufacture: designation system, chemical composition categories, heat treatment and surface finish considerations for high-temperature performance.
• Design of assemblies: guidance on bolt/nut design for reliable high-temperature service.
• Service temperature range: applicability for use at elevated temperatures up to 800 °C.
• Mechanical and physical properties: requirements for tensile strength, proof load, hardness and elongation for bolts, screws, studs and nuts.
• Test methods (ambient & high temperature):
  • Ambient tensile and hardness tests, including procedures for Rm, Rp0.2 and A where applicable.
  • High-temperature tensile, stress-rupture, relaxation and creep testing methods and reporting requirements.
  • Nut proof load and hardness tests, plus prevailing torque nut procedures.
• Inspection and conformity: applicability of manufacturer’s, supplier’s and purchaser’s inspections plus delivery of test results and documentation.
• Marking and labelling: requirements for traceability and product identification.

Practical applications and users

EN ISO 3506-5 is essential where fasteners must retain mechanical integrity at elevated temperatures. Typical applications and users include:

• Power generation, petrochemical and refinery equipment
• Furnace, boiler and heat-treatment systems
• Aerospace and high-performance engine components
• Industrial process equipment exposed to sustained high temperatures
• Fastener manufacturers, metallurgists and heat‑treatment specialists
• Design and mechanical engineers, procurement and quality assurance teams ensuring specification compliance and traceability

Benefits and keywords (SEO)

Using EN ISO 3506-5 ensures consistency in stainless steel fasteners, nickel alloy fasteners, and high temperature fastener selection, testing and acceptance. Keywords: EN ISO 3506-5, ISO 3506-5:2022, stainless steel fasteners, nickel alloys, high temperature fasteners, bolts screws studs nuts, mechanical properties, high-temperature testing.

Related standards

• Other parts of the ISO 3506 series (Parts 1–4) cover mechanical requirements for commonly used corrosion‑resistant fasteners; consult the series for material- and application-specific guidance.