Hardy Prometheus expandable rock bolts offer superior quality that respond to the most demanding roof support applications. Hardy Prometheus’s high load capacity along with excellent elongation properties ensure safer working conditions and faster excavation cycles, effectively reducing costs. The system consists of a tubular steel bolts, which have been folded inward along its entire length to reduce their diameter, a tool for installation and a water injection pump at high pressure
Application
Hardy Prometheus are recommended for rock support in mining, tunnelling and civil engineering application, where a rock reinforcement of underground excavations and temporary ground control is needed
Features
- Friction bolt with faceplate inserted, adjusted and expanded into the drill hole
- Case at the top of the friction bolt with hole to inflate the bolt pressure water
- Full view of the friction bolt
- Face plate at the top of the friction bolt: no nuts necessary
- Hardy Prometheus bolt also available with corrosion coating

Advantages
- Immediate full length support for faster excavation
- Safe and easy installation
- Excellent elongation properties
- No need for specialized crew
- Flexible for variations in drill diameter
- Versatile bolting solution
- Environmentally friendly installation
- No torquing or retorquing
- Hardy Prometheus bolts can be manufactured to any length (max. 20 ft)
Specifications
Type | Standard (120 kN) | MIDI (160 kN) | Super (240 kN) |
---|---|---|---|
Recommended Inflate Pressure | 300 Bar | 240 Bar | 300 Bar |
Tube Thickness | 2 mm | 2 mm | 3 mm |
Original Diameter | 41 mm | 41 mm | 54 mm |
Bolt Diameter | 26 mm | 36 mm | 36 mm |
Hole Diameter | 32-39 mm | 43-52 mm | 43-52 mm |
Optimal Hole Diameter | 35-38 mm | 45-51 mm | 45-51 mm |
Breaking Load | 120 kN | 160 kN | 240 kN |
Minimum Elongation | 10% | 10% | 10% |
Minimum Yield Strength | 90 kN | 130 kN | 210 kN |