The National Union of Metalworkers of South Africa (NUMSA) has announced the start of an indefinite strike.
The union is one of the biggest in the country with about 155,000 members.
The strike will affect some mining, construction, engineering and automotive companies whose employees are members.
NUMSA is seeking an 8% wage increment and subsequent 2% above inflation rate for the following two years.
Talks with the employer bodies have so far failed to reach an agreement.
“We are left with no choice but to strike and to withhold our labour indefinitely until the bosses give into our just demands,” NUMSA said in a statement.
South Africa has local plants that assemble major car brands including Ford, BMW and Nissan for export.