DYWIDAG Threadbar Rock Bolt System

Efficient load transfer with the smallest diameter boreholes.

DYWIDAG Rock Bolts are typically formed from solid threadbar systems, using a bar, nut, couplers and plates. The threadbar is used to bond unstable rock to stable sections used for tensile and shear loads.

Rock bolts are fully bonded and, unlike ground anchors, are passive installations. Thanks to the higher bond strength offered by rock compared to soil and the efficient load transfer of the threadbar, rock bolts can be installed into a much smaller hole than soil nails or ground anchors, saving time and money.

  • Less expensive construction costs versus tieback walls with soldier beams and lagging

  • Can be used for temporary and permanent applications

  • Simple components and assembly, with options for aggressive ground conditions and added corrosion protection

  • Easy to install and test

  • Durable, full-length threads allow for cutting and coupling the bar at any point along its length for easy on-site length adjustment

Main standards for steel nuances

Europe/ Asia/ Latin America: Gewi 500/550, Gewi 555/700, Gewi Plus 670/800​

UK:  Gewi 500/550, Gewi 555/700, Gewi Plus 670/800​

North America: Grade 75, 80 & 100 Threadbar Reinforcing Steel


  • Bearing plates with nuts and angle compensation

  • Borehole centralizers/spacers

  • Tremie tubes for borehole grouting from bottom up

  • Rigid or hinged lifting shackles for suspending bars

  • Double Corrosion Protection (DCP), Galvanized or Epoxy coated options for bars and hardware

  • Expansion shell and resin cartridges available

Europe/ Asia/ Latin America: Gewi 500/550, Gewi 555/700, Gewi Plus 670/800

UK:  Gewi 500/550, Gewi 555/700, Gewi Plus 670/800

North America: Reinforcing Steel Grade 75, 80 & 100 ksi (ASTM A-615), Prestressing Steel Grade 150 ksi (ASTM A-722)

Commercial & Residential Buildings