EN 1664:1997

Overview

EN 1664:1997 is a European Standard that defines the specifications for prevailing torque type all-metal hexagon nuts with a flange. This standard is based on the international ISO 7044:1997 but includes specific modifications applicable within the European context. It covers nuts with metric threads from M5 to M20, providing essential characteristics to ensure reliable performance in mechanical assemblies. The standard distinguishes product grades and property classes to address varying strength and application requirements.

Key Topics

• Nut Type and Design: Defines all-metal hexagon nuts featuring an integrated flange for enhanced load distribution and fastening stability.
• Prevailing Torque Feature: Focuses on nuts designed to maintain a secure locking action through friction generated by metal deformation, eliminating the need for additional locking elements.
• Thread Sizes Covered: Specifies dimensions and properties for metric threads ranging from M5 to M20 inclusive.
• Product Grades:
  • Grade A: Applicable to threads up to and including M16.
  • Grade B: Designed for threads above M16.
• Property Classes: Includes classifications 8, 10, and 12 to designate different mechanical strength levels suitable for varied industrial uses.
• Material and Manufacturing: All-metal construction ensures durability and resistance to environmental factors compared to composite or coated nuts.

Applications

EN 1664:1997 hexagonal flange nuts with prevailing torque are widely used in various engineering and industrial fields where secure fastening and vibration resistance are critical. Common applications include:

• Automotive Manufacturing: For securing components subjected to dynamic loads and vibrations.
• Machinery and Equipment: Used extensively in heavy machinery and construction equipment requiring reliable locking nuts.
• Structural Assemblies: Ideal for joining steel frameworks where flange nuts distribute load efficiently.
• Electrical and Mechanical Installations: Suitable for fastening electrical panels and mechanical parts with consistent preloading.
• Aerospace and Rail Industries: Utilized in applications demanding high strength and resistance to loosening under vibrations or shocks.

The prevailing torque characteristic makes these nuts especially valuable in scenarios where repeated maintenance may occur, as they maintain locking function without thread damage.

Related Standards

Professionals and engineers referencing EN 1664:1997 should also consider these related standards for comprehensive guidance on fastening components:

• ISO 7044:1997: The international counterpart detailing similar all-metal prevailing torque hexagon nuts with flange specifications.
• EN ISO 898-2: Specifies mechanical properties of nuts, essential for understanding property classes mentioned in EN 1664.
• EN 20898: Covers mechanical properties of fasteners, complementing nut specifications.
• ISO 272: Contains metric ISO general purpose screw threads dimensions, relevant for compatibility.

By adhering to EN 1664:1997, manufacturers and engineers ensure consistent quality, compatibility, and performance of all-metal flange hexagon nuts in critical fastening applications.

Keywords: EN 1664:1997, prevailing torque nuts, all-metal hexagon nuts, flange nuts, ISO 7044, metric threaded nuts, product grades, property classes, mechanical fastening, vibration-resistant nuts, European standard nuts, M5 to M20 nuts.