DYWIDAG Combo-Bolt

Immediate stabilization at any angle.

DYWIDAG Combo-Bolt is a reliable system for permanent stabilization of rock mass during the excavation of tunnels and caverns, as well as slope reinforcement. Its domed plate means it can be installed at any angle, which is useful when dealing with challenging excavated surfaces.

The support is provided in two steps – immediately through direct load transfer from anchor head, then through the grouting procedure, from the expansion shell bonding to the rock mass. This combination of technologies offers the superior advantages of immediate mechanical support for unstable rock mass and rapid optimization of the borehole size.

  • Extremely fast installation thanks to simultaneous drilling and grouting

  • Up to 120 years of service life with qualified anti-corrosion protection level

  • Reduced construction time and cost with the optimization of drillholes

  • Installation and grouting can take place at any angle

  • Angles can be compensated for at the anchor head by using a domed plate

Main standards for steel nuances

Model M22: Threadbar Ø 22mm 600/800 – Ultimate breaking load 205kN – Plate Ø 150mm​

Model M33Threadbar Ø 32mm 500/550 – Ultimate breaking load 426kN – Square Domed Plate 250x250mm


  • 3 levels of corrosion protection for the rebar on top of plastic sheathing: hot-dip galvanized or epoxy powder coating or combination of the two plus zinc phosphating

  • Can be used as permanent rock bolt, soil nail and ground anchor

  • S316 stainless dome plates and grouting bell available

  • Customization, system upgrade and modification of rock bolt system can be possible.

  • Pull out tests: test kits and site support on request