Rock Bolts

Rock bolts bond unstable rock to stable sections beyond the rock face.

Rock bolts are formed from the bar, nut, couplers, and plates of solid DYWIDAG Threadbar™ systems.

Unlike ground anchors, they are fully-bonded passive installations. 

Solid steel DYWIDAG Threadbars™ offer the most efficient means of transferring load and maintaining the smallest diameter borehole—saving time and money.


  • The continuous thread of a DYWIDAG Threadbar™ means it can be cut and coupled at any point

  • Galvanized or epoxy-coated systems of Threadbars™ and accessories are available for installations in aggressive ground conditions 

  • Double Corrosion Protection (DCP) is available for added corrosion protection

  • Galvanized or Epoxy Coated systems of Threadbars and accessories are available when installed in aggressive ground conditions and also available with Double Corrosion Protection (DCP) for greatest assurances of corrosion protection.

Rock bolts are used in

  • Ground support

  • Rock stabilization

  • Anchorages in rock

  • Rock and soil

How rock bolts work

Unless rock has been severely weathered, it will usually allow for an open hole to be drilled without any risk of collapse. 

DYWIDAG Threadbar™ is used to bond unstable rock to stable sections beyond the rockface—providing both tensile and shear loading capacity. 

Due to the higher bond strength offered by rock, in comparison with soil, rock bolts can be installed into much smaller holes than soil nails or ground anchors—saving time and money.


  • Solid threadbars or self-drilling hollow bars

  • Solid threadbar diameters 16-32mm

  • Self-drilling hollow bar diameters 25-32mm

  • Installed in restricted access locations

  • Permanent or temporary options

Retaining Structures, Shoring, Excavations

Tunnels Using Cut-and-cover Method

Slope Stabilization

The steel tendon of our fully grouted rock bolt is grouted along its entire length. A galvanized version is available and the rock bolts offer a excellent force to borehole ratio.
Our expansion shell anchors are fast and easy to install with immediate load bearing capacity in the borehole.