EN ISO 7622-2:2022 PDF

Overview - EN ISO 7622-2:2022 (Steel cord conveyor belts)

EN ISO 7622-2:2022 specifies a standardized, destructive method to measure the tensile strength in the longitudinal direction of steel cords that form the carcass of conveyor belts. It applies exclusively to conveyor belts with a steel carcass and is intended primarily for verification (for example in litigation or when a cord manufacturer’s certificate is not available). The document is the European adoption of ISO 7622-2:2022 and supersedes the 2015 edition.

Key topics and technical requirements

• Scope: Determination of longitudinal tensile strength of steel cords in conveyor belt carcasses.
• Test principle: Prepare specimens so only one warp cord is stressed and break the specimen in a dynamometric tensile testing machine.
• Apparatus requirements
  • Machine capacity such that the maximum test load is 15% to 85% of machine capacity.
  • Jaw separation rate set to (100 ± 10) mm/min and maintained constant.
  • Minimum jaw separation ≥ 250 mm.
  • Jaws designed to prevent slippage; cross-ribbed jaws with at least 80 mm ribbed length are recommended.
• Test specimens
  • Cut three specimens parallel to belt axis, at least 50 mm from edge; width containing five warp cords.
  • Length depends on cord diameter (examples): 500 mm for Ø0–3.9 mm, 700 mm for Ø4.0–5.9 mm, up to 1 500 mm for Ø13.1–15.0 mm.
  • Three specimen types (A, B, C) with defined preparation (removal of covers/weft or cutting adjacent cords to isolate the central cord).
• Conditioning: Follow ISO 18573 (use atmosphere A or B) and test immediately after conditioning.
• Procedure and results
  • Grip specimen ends (≈100 mm each) in jaws, ensure correct alignment, run test at required rate, record breaking force.
  • Tensile strength R (N/mm) is calculated as R = (F × C) / b, where F is the mean breaking force of three specimens, C the number of warp cords in the belt, and b the belt nominal width (mm).
  • The reported value is the maximum theoretical tensile strength; an effective tensile strength requires corrective factors (not detailed in this part).

Applications and who uses it

• Primary users: belt manufacturers, testing laboratories, quality assurance teams, procurement engineers, legal experts in transport/conveying disputes, and maintenance departments responsible for conveyor systems.
• Practical uses
  • Verifying compliance of steel-cord belts to contractual or forensic requirements.
  • Quality control on incoming or installed belts when manufacturer certificates are unavailable or disputed.
  • Supporting failure analysis and litigation where destructive proof of cord strength is required.

Related standards

• ISO 7622‑1 - method for determination of elongation (related part of the series).
• ISO 18573 - conveyor belts - test atmospheres and conditioning periods (normative reference used for specimen conditioning).

Keywords: EN ISO 7622-2:2022, steel cord conveyor belts, longitudinal traction test, tensile strength measurement, conveyor belt testing, test specimens, ISO 18573.