When failure is not an option. That’s the reality for mining operations moving 5,000+ tons of iron ore per hour across kilometers of rugged terrain. It’s also the reality for port terminals loading bulk carriers in 24/7 shifts, and for cement plants feeding clinker into kilns that never cool down.
In these environments, the conveyor belt is not a commodity. It is your production backbone. And when engineers specify a replacement belt for these applications, they don’t search for “conveyor belt” — they search for steel cord conveyor belt with a specific ST rating.
If you are a procurement manager, maintenance engineer, or plant director searching for a reliable steel cord conveyor belt supplier, this guide is written for you.
A steel cord conveyor belt is a heavy-duty rubber belt reinforced internally with longitudinal steel cables (cords) rather than fabric plies. The steel cords provide the tensile strength needed for:
Unlike fabric belts that stretch under sustained load, steel cord belts maintain minimal elongation (typically less than 0.25%), which means less take-up travel, less frequent re-splicing, and longer service intervals.
When you see ST630, ST1000, ST1600, or ST5400, you are looking at the tensile strength rating of the belt in N/mm (Newtons per millimeter of belt width). The higher the number, the stronger the belt.
| ST Rating | Tensile Strength | Typical Application |
| ST630 – ST1000 | 630–1,000 N/mm | Medium-duty mining, aggregate quarries, stockyard conveyors |
| ST1250 – ST1600 | 1,250–1,600 N/mm | Coal mines, cement plants, port stackers/reclaimers |
| ST2000 – ST2500 | 2,000–2,500 N/mm | Long overland conveyors, high-capacity iron ore transport |
| ST3150 – ST4000 | 3,150–4,000 N/mm | Deep shaft hoisting, extreme-lift systems, primary crusher discharge |
| ST4500 – ST5400 | 4,500–5,400 N/mm | The heaviest applications — large-diameter tunnels, mega-mine trunk conveyors |
Pro tip from our engineers: Many buyers over-specify the ST rating “just to be safe,” which drives up belt cost, pulley diameter requirements, and splice complexity. The right ST rating is the one that meets your maximum operating tension with a standard safety factor — typically 6.7:1 for steel cord belts in mining applications. Talk to our team for a free tension calculation.
Annilte operates 16 fully automated production lines using German superconducting vulcanization equipment. Every critical production parameter — temperature, pressure, dwell time — is monitored and controlled digitally. This means every meter of belt leaving our factory has traceable production data.
From ST630 to ST5400, Annilte produces the complete range. No outsourcing. No “we’ll check with our partner factory.” We manufacture what we sell, which means shorter lead times and direct accountability.
Our steel cord belts are deployed across:
The belt carcass is only half the story. The rubber cover determines how long your belt survives in your specific environment. Annilte offers:
| Cover Grade | Tensile Strength | Best For |
| A (Abrasion-Resistant) | 18–25 MPa | General mining, aggregates |
| FR (Fire-Resistant) | 15–20 MPa | Underground coal, tunnels |
| OR (Oil-Resistant) | 15–18 MPa | Oil sands, chemical plants |
| HR (Heat-Resistant) | 10–15 MPa | Cement clinker, sinter, hot ash |
| CR (Cold-Resistant) | 18–25 MPa | Arctic/sub-zero operations (down to -50°C) |
Our R&D team — 35 engineers with 16+ years of conveyor belt specialization — can formulate custom compounds for unique operating conditions.
When a gold processing plant needed a single-piece conveyor belt spanning 3.4 meters — nearly triple the industry standard width — most manufacturers said “impossible.” Annilte delivered. This same engineering mindset applies to every steel cord belt we produce: standard products for standard needs, but never a standard excuse when you need something different.