EN 3017:2008

Overview

EN 3017:2008 is a European standard developed by CEN that defines the specifications for heat resisting steel washers, specifically designed for facing and packing applications in the aerospace sector. These washers are engineered for use in non-load spreading scenarios, withstanding temperatures up to 650 °C. They are primarily used under bolt heads for clamping slotted or recessed surfaces such as brackets and pipe clippings, and for adjusting bolt grip lengths. This standard ensures compatibility with high-strength bolts classified up to 1,250 MPa. It is distinct from EN 3016, which covers washers intended for load spreading applications.

Key Topics

• Material Specifications
  The washers must be made of heat resisting steel conforming to EN 2171 or EN 2175 standards, which provide steel grades capable of maintaining mechanical properties at elevated temperatures up to 650 °C.

• Dimensions and Tolerances
  Washers are manufactured with precise dimensions and tolerances outlined in EN 3017, including thicknesses, inner and outer diameters, and flatness. Dimensions range according to bolt sizes from M3 up to M14.

• Surface Treatment
  Passivation according to EN 2516 is mandated to enhance corrosion resistance and surface durability. Surface roughness specifications are prescribed to ensure proper washer function.

• Design and Marking
  Washer configuration follows a specific shape defined by the standard, with clear guidelines on edge break and thickness variations. Marking of packages must comply with EN 2424 Style G, including quantity declaration and traceability details.

Applications

EN 3017 washers serve critical functions in aerospace assemblies where reliable clamping and heat resistance are required but without the need for load distribution. Typical applications include:

• Clamping and securing slotted or recessed bolt surfaces on aircraft brackets and pipe supports.
• Providing stable packing elements to adjust grip lengths of bolts in aerospace component assembly.
• Usage in environments with thermal exposure up to 650 °C, where heat resisting steel washers maintain integrity.
• Suitable for bolts with up to 1,250 MPa strength classification, ensuring mechanical compatibility with high-strength fasteners.

These washers contribute to the safety, performance, and longevity of aerospace structures by maintaining fastening integrity under demanding thermal conditions.

Related Standards

• EN 2171 – Aerospace series heat resisting steel bars, providing the base material specification for these washers.
• EN 2175 – Heat resisting alloy sheets and plates, relevant for alternative washer materials.
• EN 2516 – Passivation requirements for corrosion-resistant steels applied to the washers’ surface.
• EN 3016 – Washers designed for load spreading applications, which differ from the facing/packing washers in EN 3017.
• EN 2424 – Marking of aerospace products, applicable for packaging and identification of washers.
• ISO 4759-3 – Tolerances for fastener washers, offering complementary tolerance guidelines.

Keywords: aerospace washers, heat resisting steel washers, EN 3017 standard, facing washers, packing washers, high temperature washers, aerospace fasteners, aerospace bolt accessories, non load spreading washers, aerospace component clamping.