SIST EN 4057-306:2009

Overview

EN 4057-306:2006 is a CEN aerospace test method that defines the heat ageing test for cable ties used in harnesses. The standard specifies how to expose cable ties to elevated temperature and then determine their force to failure (tensile strength) and elongation at break after ageing. EN 4057-306 is intended to be used together with EN 4057-100 (general test methods) and refers to EN 4057-401 for loop tensile test apparatus.

Key topics and requirements

• Scope: Determines the force-to-failure of cable ties for aerospace harness applications after heat ageing exposure.
• Specimens: Nine specimens per material code and cross section are required.
  • Three specimens are mounted on split mandrels (for loop tensile testing).
  • Three specimens are aged flat in an oven.
  • Three specimens remain unaged as controls.
• Apparatus:
  • Tensile tester as per EN 4057-401 (loop tensile strength).
  • Laboratory oven capable of reaching the product standard’s maximum rated temperature (with the specified increase and exposure duration defined in EN 4057-306).
  • Equipment to measure elongation.
• Procedure highlights:
  • Age the specified specimens at the defined elevated temperature for the prescribed duration (nominally 500 h with tolerances given in the standard).
  • Condition specimens per EN 4057-100 before testing.
  • Perform loop tensile strength testing on mandrel-mounted specimens within 30 minutes of conditioning.
  • Prepare flat strap specimens with 25 mm free length between grips for tensile testing at (25 ± 2.5) mm/min; record elongation percentage to break.
• Pass/fail criteria:
  • Tensile strength after ageing shall meet or exceed the values specified in the appropriate product standard.
  • Elongation at break of aged flat samples shall not be less than the specified percentage compared with unaged samples, as defined in the product standard.

Applications and practical value

• Ensures long-term thermal reliability of cable ties used in aircraft wiring harnesses.
• Helps manufacturers and suppliers demonstrate compliance with aerospace material durability requirements.
• Supports qualification, acceptance testing, production control and materials selection for:
  • Aircraft OEMs and Tier suppliers
  • Aerospace cable tie manufacturers
  • Independent test laboratories
  • Certification and quality engineers

Related standards

• EN 4057-100 - Aerospace series: Cable ties for harnesses - Test methods - Part 100: General
• EN 4057-401 - Aerospace series: Cable ties for harnesses - Test methods - Part 401: Loop tensile strength

Keywords: EN 4057-306:2006, cable ties, heat ageing test, aerospace, harnesses, tensile strength, elongation, test methods, EN 4057.