STEEL CORD CONVEYOR BELT (ST)

Steel cord conveyor belts replace the fabric plies of a conventional belt with a single layer of parallel, galvanized steel cords running along the belt length. The cords are completely encapsulated in a hard core rubber that bonds chemically to the brass- or zinc-coated wire. This construction delivers the highest tensile strength of any belt type, the lowest elastic elongation (typically under 0.2 % at rated load), and minimal length growth over service life — critical for long-haul installations where take-up travel is limited.

Belts are designated ST followed by their nominal breaking strength in N/mm: ST 500, ST 800, ST 1000, ST 1250, ST 1600, ST 2000, ST 2500, ST 3150, ST 4000, ST 5400. Cord diameter ranges from about 3 mm for ST 500 up to roughly 11 mm for ST 5400, and cord pitch is selected to give a uniform tension distribution across the belt width. Because cord-to-rubber adhesion governs splice strength, all ST belts use a hot-cured vulcanized belt splice with a stepped cord pattern — mechanical fasteners are not permitted.

Typical applications include underground and surface mining overland conveyors, port shiploaders and stackers, long downhill regenerative systems, and any installation where centre distance exceeds about 1 km or where Te demand exceeds the practical limit of fabric carcasses (~1600 N/mm). Steel cord belts also accept embedded inductive loops and X-ray scanners for online splice and cord-break monitoring.