Minova Expandable Rock Bolts (EXRB) offer fast and reliable rock reinforcement with assured quality and guaranteed mechanical properties.

Minova EXRB consists of a folded steel tube with upper bushing and inflation bushing welded at each end of the tube. A specially designed adjustable face plate is delivered as an option.

EXRBs require steel that has extremely good elongation and form-ability properties. This quality produces a finished bolt that accommodates large rock movements and still maintains its high load bearing capacity. EXRBs deliver a high level of safety and uninterrupted production in the customer’s operations.

Product Image
  • Energy efficient steel production
  • EXRB may be supplied with a protective coating
  • High product quality control
Product Feature
  • High quality raw materials
  • Short lead times
  • Reliable logistics
  • Production according to ISO 9001 & ISO 14001
  • QA and certified engineered rock reinforcement product
  • Full production chain customization on request
  • Trace-ability throughout the manufacturing process

The difference between the EXRB and EXRB+ is the elongation characteristics:

• the EXRB (cold formed type) has an elongation of A5 or approximately 15%

• EXRB+ (cold formed and normalized type) has an elongation of A5 or approximately 30%.

The EXRB+ is made of unique steel which goes through a specially developed annealing process, giving the bolts their exceptional elongation characteristics while still maintaining their high load bearing capacity. This process gives the EXRB+ superior properties allowing it to accommodate large rock deformation even in highly deformable rock masses.


EXRB are available in two types, EXRB (cold formed) and EXRB+ (cold formed and normalized). Each type is available in three different load bearing capacities:
  • EXRB 120 / 120+ 12 metric tonnes
  • EXRB 160 / 160+ 16 metric tonnes
  • EXRB 240 /160+ 24 metric tonnes