In addition to operating as a sub-supplier of rock bolt, GMA also has its own manufacture and distribution of rock bolt, the so-called GE bolt. This bolt was developed after GMA had produced roughly 2.5 million rock bolts for other actors in the industry. The GE bolt is available in a number of designs adapted for cement or resin installation (see more below).
The GE bolt is supplied in the dimensions 20mm (M22), 22mm (M24) and 25mm (M27) right and left-hand threads and in lengths between 1800mm up to 3000mm*.
The GU bolt is sold and delivered directly from the factory to most export markets, while in the Nordic region the GE-bolt is distributed via Geobrugg (more information see Agents).
Feel free to contact us for more information or if variants not presented in this section are wanted.
* If a longer bolt than 3000mm is desired, bolts can be delivered in a jointable version.
GMA's dynamic rock bolt for mechanical installation in cement-filled boreholes. The GE bolt is equipped with a wedge at the top which has the task of expanding during installation and holding the bolt in place while the cement in the borehole hardens.
After hardening, it is instead the anchor points (paddles) on the bolt that act as attachment points in the event that the rock cracks / burst.
GMA´s dynamic rock bolt with a 45° cut in the top, mainly for resin installations.
The top cut and top anchor group is mixing the resin when the bolt is spun and moved upwards during the installation process.
GMA deliver the GE-bolt complete with dome plate, spherical washer and nut.
This section gives an overveiw of available assortment of these items.
