The National Union of Metalworkers of South Africa (Numsa) has started with nationwide demonstrations, while wage negotiations with the Steel and Engineering Industries Federation of Southern Africa (Seifsa) are ongoing.
Seifsa says this action has, so far, involved peaceful demonstration and not picketing.
Picketing may only be embarked on in support of a protected strike or in opposition to a lock-out, but neither parties have served strike or lock-out notices on the other.
The parties continue with negotiations on the federation’s wage offer.
Seifsa first made a wage offer on July 28, during which other trade unions indicated a willingness to accept the offer, but Numsa shortly after declared a deadlock with the federation.