Overview
EN ISO 1120:2025 defines a static test method to determine the strength of mechanical fastenings used on textile conveyor belts. The method applies to fastenings that either employ a connecting rod or do not employ a connecting rod. This standard does not cover vulcanized joints and is not applicable to light conveyor belts as described in ISO 21183-1. The primary aim is to eliminate mechanical fastenings of insufficient static strength; a complementary dynamic test is intended for future development.
Key Topics
- Principle: Application of an increasing tensile force to a prepared test piece until the fastening or belt fails.
- Apparatus: Metallic adapter plate (for fastenings with a disconnectable connecting rod) and a tensile testing machine compliant with ISO 283.
- Test piece preparation:
- Specimens taken perpendicular to the belt axis and at least 50 mm from the belt edge.
- For fastenings with a connecting rod: one longitudinal belt piece, 150 mm wide and minimum length of 100 mm plus gripped length, connected to the adapter plate by the fastener.
- For fastenings without a connecting rod: two belt pieces, each 150 mm wide and minimum length of 100 mm plus gripped length, assembled by the fastening.
- Fastening width = pitch × number of fastener plates (example given: 14 mm × 8 = 112 mm).
- Number of tests: Three test pieces per fastening.
- Conditioning and environment: Tests begin no less than 24 h after manufacture (including 8 h conditioning) under temperatures defined in ISO 18573 (Atmosphere A, B or C). In case of dispute, conditioning is 72 h.
- Procedure: Apply tensile load symmetrically and separate grips at (100 ± 10) mm/min. Record maximum force at failure.
- Expression of results:
- Arithmetic mean breaking strength in newtons per millimetre of fastening width.
- Strength expressed as a percentage of full thickness nominal tensile strength (per ISO 283).
Applications
This static test method is valuable for:
- Manufacturers checking fastener designs and quality control.
- QA laboratories performing acceptance testing of mechanical joints.
- Purchasers and specifiers assessing supplier claims and ensuring reliable joint performance.
The method helps identify fastenings with insufficient static strength before field deployment and supports consistent, documented test reporting.
Related Standards
- ISO 283 - Textile conveyor belts: full thickness tensile strength and test machine requirements.
- ISO 18573 - Conveyor belts: test atmospheres and conditioning periods.
- ISO 21183-1 - Light conveyor belts (standard clarifies that EN ISO 1120:2025 is not applicable to light belts).
For compliance and implementation, record test parameters and results in the test report including: width of fastening, fastener brand/type, belt brand/type, arithmetic mean results, failure mode, and conditioning/test temperature.