Overview
ISO 1120:2012 - Conveyor belts - Determination of strength of mechanical fastenings - Static test method - specifies a standard static test to measure the breaking strength of mechanical fastenings used on conveyor belts. The procedure applies to mechanical joints 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 (see ISO 21183-1).
Key topics and requirements
- Test principle: apply an increasing tensile force to a prepared test piece until the mechanical fastening fails; record the maximum force.
- Apparatus: metallic adapter plate (for joints with connecting rods) and a dynamometer in accordance with ISO 283.
- Test piece preparation:
- Full-thickness belt specimens cut longitudinally, minimum 150 mm width and at least 100 mm + gripped length.
- Fastening (overall width) must be ≥ 100 mm; number of hooks determined by 100 ÷ pitch, rounded up.
- Three test pieces are required per test.
- Conditioning and test conditions:
- Tests start ≥ 24 h after manufacture (includes 8 h conditioning at specified temperatures).
- Conditioning/testing temperatures: (23 ± 2) °C or (20 ± 2) °C (temperate) or (27 ± 2) °C (tropical).
- In case of dispute, conditioning period is 72 h.
- Procedure:
- Grips separated at rate (100 ± 10) mm/min; ensure symmetric loading to avoid edge-initiated rupture.
- Record maximum breaking force.
- Results and reporting:
- Report average breaking strength as newtons per millimetre (N/mm) of fastening width and as a percentage of full-thickness nominal tensile strength (reference ISO 283-1).
- Test report must include fastening width, fastener and belt brand/type, results, failure mode, and conditioning/test temperature.
Applications and users
ISO 1120:2012 is used by:
- Conveyor belt manufacturers and fastener suppliers for quality control and product development.
- Testing laboratories and inspection bodies performing mechanical fastening strength verification.
- Mining, bulk material handling, and heavy-industry operations that rely on robust mechanical splices.
Practical benefits include eliminating mechanically inadequate fastenings and establishing consistent, repeatable static-strength data for procurement and safety decisions.
Related standards
- ISO 283 - referenced for dynamometer and tensile properties (full-thickness tensile strength).
- ISO 21183-1 - covers light conveyor belts (ISO 1120:2012 is not applicable to these).
Keywords: ISO 1120:2012, conveyor belts, mechanical fastenings, static test method, breaking strength, dynamometer, connecting rod, N/mm, conveyor belt testing.