MEGABolt Water Expandable Rock Bolts (ERB)

MEGABolt Water Expandable Rock Bolts (ERB) are full-column anchored friction rock bolts that use high-pressure water to hydroform and expand inside a drilled borehole. Reinforcement occurs by expanding the bolt with high-pressure water against the drill hole wall, causing the bolt to take the shape of the hole and create a friction and interlocking anchor that provides immediate full load-bearing capacity.

When high-pressure water is pumped into the bolt, the ERB expands into the shape of the hole, forming a mechanical interlock between the borehole wall and the bolt over the full bolt length. When the pump stops, the ERB immediately provides full rock support action.

The MEGABolt Friction Range consists of three products that each provide 30% elongation: the Standard model for lighter applications with a load capacity of 12 metric tons (120 kN), the Midi with a load capacity of 16 metric tons (160 kN), and a heavy-duty variant for the most demanding applications.

The MEGABolt Water Expandable Rock Bolts range features friction bolts with superior product characteristics to meet the most demanding roof support applications. They are widely used in underground mining, tunnel construction, civil engineering excavations, and anywhere ground stabilisation is critical.

MEGABolt Water Expandable Rock Bolts utilize hydroforming technology to achieve superior anchoring capacity by expanding within drilled holes, enabling faster shotcrete placement, reduced installation time, and improved safety margins advantages that conventional grouted or mechanical bolts cannot match simultaneously.

Yes. Installation is easy and flexible to fit various drill hole diameters, providing immediate full load-bearing capacity with safe installation. This flexibility reduces the need for precise hole sizing on-site, saving time and labour costs.

The MEGABolt Friction rock bolts are manufactured according to ISO 9002 standards, and each batch of finished rock bolts is tested to ensure final quality. This ensures consistent performance across every project.

The primary anchorage mechanism in expandable rock bolts is mechanical friction generated by the expansion of the bolt against the borehole wall, providing immediate support action. Unlike split sets, ERBs expand over the full bolt length and also tension the face plate due to length contraction during inflation, delivering superior holding strength.

When the Expandable Rock Bolt is inflated, it causes a contraction in bolt length, which effectively tensions the face plate, adding an active pre-load component to what is otherwise a passive friction support system.

Yes. MEGABolt ERBs offer flexible installation that fits various drill hole diameters, simplifying site logistics and making them suitable for conditions where borehole consistency is difficult to maintain due to fractured or weathered rock.

Argentium, headquartered at 79 Shyam Lal Rd, Daryaganj, New Delhi, is India’s leading manufacturer and supplier of MEGABolt Water Expandable Rock Bolts (ERB) along with a full range of tunneling, mining, and ground support products.

MEGABolt Water Expandable Rock Bolts are available at approximately ₹400 per metre. Final pricing may vary depending on bolt variant (Standard, Midi, or heavy-duty), order volume, and project specifications. Contact Argentium at admin@argentium.in for a custom quote.

The high load-bearing capacity and excellent elongation properties ensure safer working conditions and faster excavation cycles at lower costs. The 30% elongation across all three product variants allows the bolt to absorb dynamic loads and rock movement without sudden failure, critical in seismically active or stress-prone underground environments.

MEGABolt ERBs enable faster shotcrete placement, reduce installation time, and improve safety margins because there is no waiting period for grout to cure, the bolt is active the moment the pump stops, allowing excavation to continue immediately after installation.

Alongside the MEGABolt Water Expandable Rock Bolts (ERB), Argentium’s MEGABolt range includes the MEGA Splice Coupling System, MEGABolt-GFRP Self Drilling Anchor, and MEGABolt-PT Bar, offering a comprehensive ground support solution for diverse geological conditions across mining and tunneling projects.