Abstract: A safety plug for use in rock drilling operations. The safety plug includes a base part and one or more expander elements. The base part has a leading end and a trailing end and a generally cylindrical outer surface between the leading and trailing ends, on which one or more external spirals are formed. The external spirals are provided to engage the internal wall of a bore within which the safety plug is inserted to anchor the base part within the bore. The one or more expander elements have an inactive non-expanded condition and an active, laterally expanded condition. The safety plug is operable to absorb load applied to its leading end in two stages, whereby: in a first stage, load applied to the leading end of the one or more expander elements up to a predetermined load is transferred to the base part and the base part is operable to react the load by engagement of the spirals with the internal wall of the bore.