Resin Bolts

Resin bolts are designed to be used for roof and ribs support in mine working areas as an independent or additional roof support system. They are also used for the attachment of various components of mining equipment.

Resin bolts are modern design anchors with load capacity of up to 300 kN and a nut locking system (shearpin).
Anchor rod is made from a reinforcing bar of 21.70 mm in diameter according to ZN-95/AP-1; ZN-02/AP-6 made of different types of steel.

M24 nut is connected with the rod by means of a “SPIROL” fi-3 or fi-6 pin. Spherical washer makes it possible to fix the anchor at 18°angle. The anchor can be used with a square, round or square washer with an eyelet made of 8 or 10 mm plate.

Put resin cartridges in the drill hole. Insert the anchor and rotate while pushing causing the resin to mix. During mixing, the nut does not turn as it is joined with the rod by means of a fi-3 or fi-6 pin. Once the resin has set, the pin is sheared by turning the nut. Apply torque of at least 250 Nm to screw on the M24 nut in order to tension the anchor to the desired prestress (initial tension) of minimum 30 kN.

Measurement of frictional torque of threads in bolt

The torque is applied by means of suspending the weights on one end of the rope and other end is wound around the head of the bolt and tied to the projection. The amount of load is increased gradually till the bolt starts rotating. The applied load is then calculated by adding up the weights. This is the load that is required to overcome the friction between the threads. Similarly the net applied torque is calculated by multiplying the resultant load by bolt head radius.