ISO 7590:2018

Overview - ISO 7590:2018 for steel cord conveyor belts

ISO 7590:2018 specifies standardized methods for measuring total thickness and cover thickness of steel cord conveyor belts. It defines three approved measurement techniques: Method A1 and Method A2 (micrometer methods) for both total belt thickness and cover thickness, and Method B (optical method) for cover thickness only. The standard sets measurement locations, specimen requirements, apparatus specifications and reporting requirements to ensure consistent, repeatable thickness testing for quality control and compliance.

Key topics and technical requirements

• Scope and purpose: Measurement of total belt thickness and thickness of top/bottom covers of steel cord conveyor belts.
• Measurement points:
  • Belts ≤ 1 000 mm wide: measure at 3 equidistant points.
  • Belts > 1 000 mm wide: measure at 5 equidistant points.
• Methods:
  • A1 / A2 (micrometer methods): suitable for all steel cord conveyor belts; involve cutting test specimens and using a dial gauge micrometer for total and cover thickness measurement.
  • B (optical method): hand-held magnifier with scale for cover thickness only; not suitable if a textile or metal weft is present or if cord ends twist when cut.
• Apparatus:
  • Dial gauge micrometer graduated every 0.1 mm, flat feet with a 10 mm diameter circular foot, applying pressure of (22 ± 5) kPa.
  • Optical instrument: magnification ≥ 8×, scale in 0.1 mm steps.
• Specimen preparation: rectangular test pieces cut at 90° to belt edge; A1 specimens typically ~150 mm long and two cord pitches wide; A2/B require minimum lengths and full-width or marked measurement points.
• Result calculation: arithmetic mean of the 3 or 5 measurements (as applicable) expressed in millimetres.
• Test report must include reference to ISO 7590, method used (A1/A2/B), belt identification, number of points, test results and date.

Applications and users

ISO 7590 is used by:

• QA/QC laboratories and manufacturing inspection teams at conveyor belt manufacturers
• Third‑party testing and certification bodies
• Procurement and acceptance testing teams in mining, bulk handling, ports, aggregates and materials handling
• Engineers specifying belt construction in design and maintenance contracts

Practical uses include routine quality control, incoming material inspection, contractual acceptance testing, failure analysis and R&D comparisons of cover formulations or carcass designs.

Related standards

• ISO 8094 - Adhesion strength test of cover to the core layer (related test pieces can be shared with ISO 7590 A1).
• EN 13827 - Determination of lateral and vertical displacement of steel cords (related to A2 specimen use).

Keywords: ISO 7590, steel cord conveyor belts, cover thickness, total thickness, micrometer methods, optical method, conveyor belt testing, measurement standards.