oSIST prEN 2948:2026

Overview

oSIST prEN 2948:2026 is a European standard developed by CEN that specifies the technical requirements for aerospace tab washers made of heat-resisting steel, passivated. These washers are designed for aerospace applications where they must withstand maximum operating temperatures up to 650 °C. This standard covers the dimensions, material specifications, surface treatments, testing methods, and quality assurance practices for tab washers used under hexagon head bolts. The washers must meet strict aerospace quality and safety criteria to ensure reliable performance in demanding environments.

Key Topics

• Scope and Application
  oSIST prEN 2948:2026 applies specifically to tab washers made of heat-resisting steel suitable for high-temperature aerospace environments. Their use under hexagon head bolts requires users to accept potential interference issues.

• Material Requirements
  The heat-resisting steel conforms to EN 2175 standard (FE-PA2602 alloy), which ensures strength and durability at elevated temperatures. Passivation is conducted as per EN 2516 to enhance corrosion resistance.

• Dimensions and Configuration
  Detailed dimensions and mass codes are standardized and include precise tolerances. The washers feature a tab design to secure assemblies effectively, with specific measurements expressed in millimeters.

• Surface Treatment
  Passivation treatment is mandatory to improve corrosion resistance, ensuring longevity and safety in critical aerospace conditions.

• Testing and Inspections
  Visual inspections check for burrs, scratches, and cracks. A mandatory bend test verifies that locking tabs can be folded and straightened without cracking, ensuring mechanical integrity.

• Quality Assurance
  Manufacturers must comply with aerospace quality management systems such as EN 9100 or equivalent standards. Qualification tests follow procedures such as EN 9133 for aerospace standard products.

• Marking and Designation
  Washers are marked following EN 2424 guidelines for aerospace product identification to ensure traceability and compliance with aerospace supply chain requirements.

Applications

oSIST prEN 2948:2026 tab washers are primarily used in aerospace assemblies where components are subjected to high temperatures approaching 650 °C. Typical applications include:

• Securing fasteners in aircraft engines, turbines, and exhaust systems
• Ensuring mechanical locking under hexagonal bolts in aerospace structural components
• Providing heat-resistant, corrosion-protected locking elements in aerospace mechanical systems where reliability under thermal stress is critical
• Used where passivation and surface treatment are necessary to prevent corrosion in aggressive environments

The standard supports aerospace manufacturers, maintenance organizations, and quality controllers aiming to procure or produce tab washers compliant with strict aerospace operational requirements.

Related Standards

• EN 2175 - Aerospace series alloy specification for heat-resisting steel used in tab washers
• EN 2516 - Passivation processes for corrosion-resistant steels applicable to washer surfaces
• EN 2424 - Marking requirements for aerospace products ensuring unique product identification
• EN 9100 - Aerospace quality management systems standard for manufacturers
• EN 9133 - Qualification procedures specifically for aerospace standard components like tab washers

Summary

oSIST prEN 2948:2026 sets a comprehensive framework for tab washers in heat-resisting, passivated steel designed for the aerospace industry. It ensures that these locking elements meet stringent quality, durability, temperature resistance, and corrosion protection standards essential for aerospace safety and performance. By adhering to applicable dimensions, materials, surface treatments, and testing protocols, aerospace manufacturers can achieve reliable fastening solutions suitable for extreme operating temperatures, securing critical mechanical joints in aircraft and spacecraft applications.

Keywords: Aerospace tab washers, heat resisting steel washers, passivated washers, oSIST prEN 2948:2026, aerospace fasteners, high temperature washers, aerospace locking elements, aerospace quality standards, EN 2175 steel, EN 2516 passivation, aerospace bolt washers, aerospace components.