Direct answer: Choose the ground support system by the ground's behavior and how quickly support must act. Split sets (friction bolts) give immediate, full-length frictional support the moment they are driven — ideal for fast-advancing headings, blocky or squeezing ground, and as a first-pass support in seismic conditions. Resin bolts provide high, rigid anchorage once the resin sets, ideal for permanent reinforcement in stable ground. Cable bolts are for long, heavy anchorage in large spans, high walls, and deep failure zones. In most modern underground mines the answer is a combination: split sets for immediate support at the face, resin bolts for permanent reinforcement, and cable bolts for large openings — sourced from one supplier so the system is designed together.
Split set (friction bolt): a slotted steel tube driven into a smaller hole; the slot closes and the tube grips the rock by friction along its entire length. Support is active immediately — there is no curing time.
Resin bolt: a solid bar anchored by resin cartridges that are mixed as the bolt is spun into the hole. Anchorage develops as the resin cures (typically minutes to tens of minutes), producing a stiff, high-capacity bond.
Cable bolt: a flexible steel cable grouted (or resin-anchored) into a hole, used for long, heavy reinforcement across large spans and deep stress-relief zones.
Each has a different strength: split sets for speed and ductility, resin bolts for stiffness and capacity, cable bolts for length and flexibility. The selection question is which behavior your ground needs.
| Factor | Split set (friction bolt) | Resin bolt | Cable bolt |
|---|---|---|---|
| Support activation | Immediate (on driving) | After resin cures | After grout/resin sets |
| Anchorage type | Full-length friction | Full-column resin bond | Full-length grout bond |
| Installation speed | Very fast | Moderate | Slower |
| Rigidity / capacity | Moderate, ductile | High, stiff | Very high, long reach |
| Typical length | 0.45–3 m (and beyond) | 1.5–3 m (common) | 6–15 m+ |
| Best for | Immediate face support, blocky/squeezing ground, seismic | Permanent reinforcement, stable ground | Large spans, high walls, deep failure zones |
| Relative cost | Low–moderate | Moderate | High |
Split sets are the workhorse of immediate ground support, and the reasons are practical:
Support the instant the bolt is driven. There is no wait for resin or grout to cure — critical in blocky ground where time is safety.
Fast installation with minimal equipment. Faster cycle times in development headings mean more advance per shift.
Ductile, not brittle. A split set yields and deforms with the rock rather than snapping — valuable in squeezing or seismic ground where stiff bolts can fail suddenly.
Cost-effective at volume. For large headings and bolt-heavy ground-control plans, split sets are typically the most economical full-length support.
This is why split sets are a preferred first-pass support in high-stress underground mines — for example, the Australian underground mines that prefer friction bolts for seismic and squeezing conditions. See our friction bolt range, including the heavy-duty FB-47, mid-range FB-39, and FB-33.
Resin bolts earn their place when the ground is stable enough to wait for curing, and the goal is stiff, permanent reinforcement.
High, rigid anchorage. The full-column resin bond delivers high capacity and minimal deformation once cured.
Permanent support. For long-life openings, service tunnels, and permanent infrastructure where support must hold for years.
Controlled installation. Resin bolts require clean holes and correct mixing — quality depends on disciplined installation and the right resin/hole geometry.
Resin bolts are often specified as the second support layer: split sets secure the face immediately, then resin bolts provide the long-term reinforcement.
Cable bolts are the heavy, long-reach tool for large openings and deep ground problems.
Large spans and high walls. Stopes, caverns, and intersections where the failure zone extends well beyond normal bolt lengths.
Deep stress-relief zones. Where the rock needs to be held together over several metres, not just at the surface.
Flexibility. Cable bolts can be installed in irregular holes and around equipment where a rigid bar cannot go.
Cable bolts carry a higher cost and slower installation, so they are reserved for the situations where their length and flexibility are genuinely required.
Most modern mines do not choose one system — they combine them in layers:
Split sets at the face for immediate, full-length frictional support the moment the rock is exposed.
Resin bolts behind the face for permanent, stiff reinforcement of the opening.
Cable bolts at intersections, stopes, and large spans for deep anchorage.
Mesh and plates to retain loose rock between bolts.
Designing the layers together — rather than buying each from a different supplier — reduces compatibility gaps and installation delays.
Tanrimine Metal Support Co., Ltd (TRM) is a professional manufacturer of friction bolts and bearing plates, plus a full range of accessories and related components, for mining, tunnelling, and dam projects.
Production capacity: 30,000 tons annual capacity of friction bolts and related products, with large stock of regular items for quick delivery.
Quality: production under ISO 9001 with a double-track quality control system from raw material to finished product — see our quality control page.
R&D: an in-house R&D team that can design new bolts and plates and put them into production quickly.
Mission: safety is always our top priority — ground support is a life-safety product.
A ground support system only works if the components are configured to fit each other and the ground. When you order, confirm:
Bolt diameter and length matched to drill-hole size and ground conditions.
Bearing plate type and size matched to the load — dome, combi, duo, strata, or flat plates each suit different surface and load conditions.
Mesh where blocky ground requires surface retention between bolts — see our weld mesh.
Coating (black, cold-galvanized, or hot-dip galvanized) matched to the corrosion environment.
Accessories — drivers, pull collars, rings — so installation is correct from day one.
For split sets specifically, confirm the pull-test procedure is part of the plan — see our bolt pull-test page.
Installation errors are a leading cause of support failure — often independent of which system you choose. The most common, and how to prevent them:
Wrong hole size (split sets). A worn bit over-drills the hole and reduces friction, so the bolt will not grip. Use the correct bit for the bolt diameter and replace worn bits. The hole must be slightly smaller than the bolt's nominal diameter.
Hole too shallow (all systems). A bolt that bottoms out before seating cannot develop full anchorage. For split sets, drill at least 150 mm deeper than the bolt length.
Driving past the plate (split sets). Once the plate is firmly against the rock, stop driving — continuing damages the bolt end and the anchorage.
Resin not fully mixed or hole not clean (resin bolts). Dirty or oversized holes and incorrect spin times produce a weak resin bond. Follow the resin manufacturer's mixing time and hole-cleaning procedure exactly.
Insufficient grout or resin fill (cable bolts). Poor filling leaves gaps along the cable and reduces bond. Verify full-column filling before the grout sets.
Off-perpendicular installation. Bolts driven at a steep angle to the rock surface do not seat the plate properly. Drive as close to perpendicular as practical.
Skipping pull tests. Without pull testing after installation, an under-performing installation goes undetected until ground moves. Make pull testing part of the standard procedure.
Underground metal mines (gold, copper) using split sets for immediate roof and wall support in high-stress, seismic ground.
Tunnelling projects where split sets provide support directly behind the advancing face.
Slopes and dams where immediate full-length anchorage stabilizes rock faces and abutments.
Custom ground-support projects where our R&D team has designed and tested new bolt types for specific conditions.
We supply ground-support projects across mining, tunnelling, and civil works worldwide. When evaluating any supplier, ask for the specific diameters, certified test values, coatings, and applications behind the catalogue.
Specify exactly. Diameter, length, steel grade, coating, plate type, and quantity — in writing — so there is no ambiguity about what will be delivered.
Confirm MOQ and lead time. Standard sizes are usually available from stock; custom sizes, lengths, or plates may carry a higher MOQ and longer lead time.
Request certified test data. Yield, tensile, and elongation for the exact product you order, not a generic catalogue number.
Confirm packaging. Friction bolts are typically bundled (e.g., 100–300 pieces per bundle); confirm bundling and any export packing requirements for sea freight.
Agree delivery terms. Confirm the shipping method and who bears freight and customs, and confirm the supplier can meet urgent requirements — TRM's 30,000-ton capacity and regular stock are built for this.
Start with a trial. For a new supplier, order a trial batch and pull-test on site before committing to a full programme.
Technical support. Confirm the supplier can help with selection, installation, and pull-test interpretation — not just ship boxes. TRM's engineering team supports selection and design.
Quality assurance. A supplier with ISO 9001 and double-track quality control can trace any product issue back to its production batch.
R&D responsiveness. If site conditions change, a supplier with in-house R&D can adapt the bolt or plate quickly — an advantage a pure trader cannot offer.
Clear communication. A named contact and a defined process for technical and warranty questions protect you after the invoice. Reach us at jimwang@cnort.com.
Monitor critical ground. Combine support with convergence monitoring in high-stress areas to confirm the system is holding.
Scheduled pull testing. Periodic pull tests verify anchorage over time, especially in dynamic or squeezing ground.
Inspect for corrosion. In wet ground, monitor coating condition; uncoated or under-specified bolts can corrode and lose capacity.
Check plates and mesh. Look for loose plates or damaged mesh, which indicate load redistribution that needs attention.
Store spares correctly. Keep uninstalled bolts dry and off the ground, and protect galvanized surfaces from handling damage.
Neither is universally better — they serve different purposes. Split sets give immediate, ductile, full-length support and are ideal at the face and in blocky or seismic ground; resin bolts give stiff, high-capacity permanent reinforcement once cured. Most mines use both in sequence.
Yes, when selected and installed correctly — with the right diameter, length, coating, and plate for the ground and environment. In permanent openings, they are often combined with resin or cable bolts for long-term reinforcement.
Because they are ductile: they deform with the rock instead of snapping suddenly, and they provide support along their full length immediately, without waiting for resin to cure.
TRM has an annual capacity of 30,000 tons of friction bolts and related products, with large stock of regular items for quick and urgent delivery.
Yes. We manufacture friction bolts and bearing plates, and supply the full range of accessories and mesh, so the whole system is designed and sourced together.
Yes. Our in-house R&D team can design a new bolt or plate and put it into production quickly, supporting non-standard projects as engineering work rather than off-the-shelf sales.
Need help choosing the right ground support system?
Send your ground conditions, drill plan, and load requirements to jimwang@cnort.com, or explore our friction bolts, plates, and mesh.
