Mechanical Anchored Rock Bolts (Roof Bolts)

Rock bolts / studs are mechanically point anchored within the rock using 3 leaf bail-type expansion shells attached to the inserted end of the bolt. Expansion shells are supplied screwed onto the end of the rock tendon and are inserted into the hole.

When tension is applied to the tendon the tapered plug within the shell forces the leaves to move outwards, thus wedging them against the walls of the borehole. This means that the mechanical bolt is functional immediately on installation. In many applications the installation is post-grouted for additional stability. The complete rock bolt assembly includes the threaded bar, bearing plate (washer), nut, seat and expansion shell.

Numerous combinations are available to suit individual strata control requirements. These include:

  • Bar Type
  • Bar diameter
  • Thread type
  • Expansion shell size
  • Washer profile
  • Washer dimensions
All round and deformed bar (ribbed bar) used for mechanical anchors is high tensile (minimum 480 MPa) steel hot rolled in accordance with SABS 920. Step Bar® and Katbar® are specifically designed for mining applications (please refer to the individual Product Information Sheets for more detail).

Advantages of the Product:

  • Mechanical Anchors provide immediate active support.
  • Wide choice of combinations to meet specific support requirements.
  • Can be post grouted.
  • The wedge and leaf arrangement provides parallel contact with the hole sides.
  • Up to 4 mm range in hole diameter can be tolerated (depending on the choice of shell).

Legal Notice: OEM Brand names have been used for reference purposes only, and are not products or brands marketed by Kuplak Minerals Africa (Pty) Ltd.