1. What Is Split Set Rock Bolt?
Split set rock bolt, also known as friction rock bolt or slotted tube anchor, is a passive roadway support component widely used in underground mines and tunnels.
It is made of seamless steel tube with a longitudinal split along the whole length. After driven into drill holes, the tube expands tightly against rock walls by elastic deformation, generating continuous friction force to fix loose rock strata and prevent roof collapse.
Compared with resin anchoring systems, split set bolts feature fast installation, no chemical medicine, low construction cost and reusable simple construction tools, becoming the preferred supporting product for soft rock, broken surrounding rock and temporary roadway support.
2. Core Working Principle
- Drill round holes matching the outer diameter of split set bolt in rock layer;
- Hammer the split tube anchor fully into the borehole;
- The slotted steel tube is compressed inward, producing lasting radial extrusion friction with hole wall;
- Uniform friction force locks surrounding rock blocks, restrains rock deformation and crack expansion.
3. Main Advantages of Split Set Rock Bolts
- Ultra-fast installation: No mixing resin, no waiting for curing, greatly improve tunneling efficiency
- Strong adaptability: Fits broken, soft, loose rock layers unsuitable for resin anchors
- Low comprehensive cost: Simple accessories, no supporting chemical anchoring agent
- Good shock resistance: Absorb blasting vibration, not easy to lose anchoring force
- Complete matching accessories: Supporting steel pallet, flat washer to disperse pressure
- Stable long-term friction holding force, reduce later maintenance frequency
4. Common Specifications & Parameters
Standard Sizes
- Outer diameter: 33mm, 39mm, 43mm, 47mm, other custom sizes available
- Usual lengths: 1.0m, 1.2m, 1.5m, 1.8m, 2.0m, 2.4m, customized per project drawing
Raw Material & Surface Treatment
- Material: High toughness seamless carbon steel tube
- Surface options: Black anti-rust finish, electro galvanized, hot-dip galvanized
Matching Accessories
Square anchor tray, round pallet, flat iron washer, installation driving bit
5. Main Application Scenarios
- Coal mine underground roadway temporary & permanent support
- Metal mine, iron mine, gold mine surrounding rock reinforcement
- Mountain highway tunnels, hydropower underground caverns
- Slope stabilization, small underground engineering support
- Emergency rapid support for broken rock sections
6. How to Judge High-Quality Split Set Bolts
Many buyers encounter inferior split tubes with insufficient toughness, easy bending and weak friction force. Qualified products must meet the following standards:
- Thick-walled seamless steel tube, uniform wall thickness without thinning
- Moderate slit width, good elastic rebound after extrusion, no permanent deformation
- Strict raw material toughness test, not brittle under underground impact
- Smooth tube surface without burrs, convenient for hammer-in installation
- Uniform anti-rust coating, adapt to humid underground mine environment
- Factory tensile friction test report provided for project inspection
7. Sourcing Split Set Bolts From Our Factory
We are a professional mining support hardware manufacturer with full split set bolt production lines, integrating tube cutting, slitting, shaping and surface anti-corrosion treatment.
Our Supply Strengths
- Full size inventory for regular split set rock bolts, short lead time for urgent project orders
- Custom size, wall thickness and surface treatment according to client engineering requirements
- Free test samples for tension and friction test before mass bulk order
- Complete factory inspection certificates, supporting mine tender and import customs clearance
- Wholesale discount for large mine projects, exclusive regional agent policy available
- One-stop matching supply: supporting pallets, washers, resin anchors, threaded rock bolts, mining fasteners
8. Installation Tips for Split Set Anchors
- Control drilling hole diameter strictly per bolt outer diameter to guarantee friction holding force;
- Keep borehole clean without excessive rock powder;
- Equip complete steel pallet during installation to avoid local stress concentration;
- For heavily broken rock layers, cooperate with welded mine wire mesh for combined support.
Post time: 2026-07-02 17:15:47
