Drilling Solutions for Mining & Tunneling
Application Overview
Mining and tunneling projects demand drilling tools that perform reliably in hard rock, fractured ground, and high-dust underground environments. From installing thousands of rock bolts for tunnel support systems to probe drilling for geological assessment, the right tooling determines advance rates, support cycle times, and operational safety. Zhonghuan supplies SDS-Max bits for deep rock drilling, SDS-Plus bits for lighter anchor work, hammer chisels for demolition and rock scaling, and bushing bits for shotcrete surface preparation — all factory-direct with OEM flexibility for mine shaft reinforcement, tunnel support, and underground infrastructure projects.
Recommended Product Lines
| Product | Size Range | Application |
|---|---|---|
| SDS-Max Hammer Drill Bits | 12-52 mm x 340-920 mm | Rock bolt holes, anchor bolt installation, deep probe drilling in hard rock |
| SDS-Plus Hammer Drill Bits | 5-25 mm x 110-600 mm | Secondary anchoring, mesh pin holes, lighter fixing work in softer rock |
| Hammer Chisels (SDS-Max) | Pointed / Flat 25-80 mm / Scaling | Rock scaling, loose material removal, demolition, overbreak trimming |
| Bushing Bits | 60-80 mm (9-point, 16-point) | Surface roughening for shotcrete adhesion, laitance removal |
| Diamond Core Drills | 25-100 mm | Geological sampling, probe holes, grout injection ports |
Application Scenarios
1. Rock Bolt Installation
Material: Hard rock, medium rock, fractured ground
Recommended: SDS-Max 2-cutter or 4-cutter bit, 16-25 mm x 500-920 mm
Notes: Drill diameter must match the rock bolt specification exactly. Hole depth = bolt length + 50 mm clearance for resin cartridge or grout. In fractured rock, reduce impact energy to prevent hole collapse. For fully grouted bolts, maintain straight holes — use full-head carbide geometry. Clear cuttings frequently in deep holes to prevent bit jamming.
2. Tunnel Shotcrete Surface Preparation
Material: Excavated rock face, concrete substrate
Recommended: Bushing bit 60-80 mm, 9-point or 16-point pattern
Notes: Surface roughening is critical for shotcrete bond strength. The bushing bit creates a consistent 3-5 mm profile depth that meets adhesion specifications. Work in systematic overlapping passes across the entire surface. Remove all loose material and laitance before shotcrete application. Use a 5-7 kg class SDS-Max hammer at controlled impact energy to avoid over-fracturing the substrate.
3. Probe Drilling for Geological Assessment
Material: Variable geology — rock, clay, mixed ground
Recommended: Diamond core drill, 50 mm diameter
Notes: Probe holes ahead of the tunnel face assess water inflow risk, fault zones, and ground conditions before excavation. Diamond core drills recover intact samples for geological logging. Wet drilling is essential — it cools the segments, flushes cuttings, and prevents core damage. Mark core orientation before extraction for accurate geological mapping.
4. Secondary Support Anchor Installation
Material: Rock with primary shotcrete layer, concrete lined tunnels
Recommended: SDS-Plus 4-cutter bit, 12-16 mm x 160-450 mm
Notes: Secondary anchors secure mesh, steel sets, and supplementary support elements. SDS-Plus bits are sufficient for these shorter, smaller-diameter holes. Use 4-cutter geometry when drilling through shotcrete into rock — it handles the material transition without stalling. Drill perpendicular to the rock face for maximum anchor pull-out strength.
5. Rock Scaling and Loose Material Removal
Material: Blasted rock, fractured ground, loose overbreak
Recommended: Pointed chisel for primary scaling; flat chisel (40-60 mm) for slab removal
Notes: Scaling removes loose rock that poses a fall hazard after blasting. Use a pointed chisel to find natural fracture planes and pry loose blocks. Switch to flat chisel for trimming protruding rock and cleaning the profile. Work from a safe position — always scale from stable ground toward the face. Use a 7-12 kg class SDS-Max demolition hammer with anti-vibration handle for operator safety during extended scaling shifts.
6. Production Blast-Hole Drilling (Small-Scale Mining)
Material: Medium to hard rock at the working face
Recommended: SDS-Max mining bit, Ø32 mm × 450–920 mm — 6-cutting-edge head for medium rock, ZHMAX-7 multi-segmented cutter for hard abrasive rock
Notes: Hand-held 10 kg-class rotary hammers drill 32 mm × 450–800 mm blast holes at roughly 15° into the face for ø25 mm explosive cartridges. Retire bits on gauge wear — an under-size hole stops the cartridge short of the bottom. Full OEM program: SDS-Max mining drill bits manufacturer; field engineering: rotary-hammer blast-hole drilling guide.
Selection Guide
- Rock hardness: Soft rock (UCS below 80 MPa) = standard carbide. Medium rock (80-150 MPa) = reinforced carbide. Hard rock (above 150 MPa) = premium carbide grade with full-head geometry.
- Hole depth: Under 500 mm = standard SDS-Max. 500-920 mm = long-series SDS-Max. Over 1 m = consider extension systems or diamond core drilling.
- Anchor type: Expansion shell bolt = precise diameter match. Resin bolt = diameter + 2 mm for cartridge fit. Friction bolt (Split Set/Swellex) = manufacturer-specified diameter.
- Surface preparation: Shotcrete adhesion = bushing bit. Rock trimming = flat chisel. Loose rock removal = pointed chisel.
- Volume: High-cycle rock bolting (100+ holes per shift) demands premium carbide bits — the cost-per-hole drops significantly versus standard grades due to longer bit life.
Ordering Information
- ISO 9001 Certified — documentation supplied with every shipment
- MOQ: Reviewed case-by-case based on product scope, specification mix, and packaging
- Production timing: Confirmed after specification and capacity review
- Packaging: Industrial bulk, retail blister, or custom branded
- Private Label: Laser etching + custom packaging available
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