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.
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.