This paper outlines the mechanism of Stress Corrosion Cracking
(SCC) and how it can cause premature failure of rock bolts. SCC
occurs due to the progressive development and growth of cracks
in the surface of a metal, and it is caused by the combined
effects of stress and a corrosive environment affecting
susceptible metals and alloys. It can occur in most metals
including stainless steel. It is not a new phenomenon, but its
effect on rock bolts has only been recognised recently. Rock
bolt failures caused by SCC appear to be brittle failures which
occur at less than the ultimate tensile strength of the bolt. In
the mining industry , SCC failures of rock bolts can occur a few
months, or after many years of exposure to stress and a
corrosive environment. If SCC of rock bolts is suspected, then
thl~ rock bolts should be examined by a metallurgist, and steps
should be taken to reduce the problem. Considerable research in
the past has shown that SCC is a complex phenomenon and no one
mechanism can explain all cases