Rock Bolt Extension Coupling

Physical Properties

Thread Size	Length	Net Weight
	mm	kg
M24x3.0 pitch	360	1.9

General Features

The Rock Bolt Extension Coupling is a specialty product used to extend rock bolts to ensure the bolt end does not protrude from the rock after the bolt has completed its purpose, i.e. boot ends, drive heads etc. are secured. This ensures no subsequent damage occurs to rubber tyred vehicles.
The Rock Bolt Extension coupling was designed to be recoverable after use to allow reinstallation or re-use at other locations.
Manufactured from higher tensile steel, the Extension Coupling will match or better the tensile properties of current 24mm rock bolts.

Installation Guidelines

Each bolt hole is drilled 27-28mm diameter and to a depth 150mm longer than the bolt. The hole mouth is reamed out at 36mm for a depth of 200mm to accept the Extension Coupling.
The Extension Coupling is fitted to the rock bolt with a domed plate washer.
After insertion of the chemical anchors, rotate the coupling by the nut fitted to the Extension Coupling, through the anchor, while pushing the bolt to the back of the hole. A machine capable of minimum 200 r.p.m. should be used for mixing.
The second nut is then tightened to secure the equipment.
To remove and reclaim the Extension Coupling for use at another location, undo the tensioning nut, then rotate the fixed nut anti-clockwise to remove the unit.

Notes

Only DSI rock bolt components should be used in order to obtain full performance of the bolt system.
DSI's Mining Products Division is Quality Assured to ISO 9001:9002, Registration No. QAC/R61/0315.

PRINTED December 2006: All dimensions, weights, quantities and specifications are those applicable at the time of publication and may be amended from time to time.