Numsa spokesperson Dumisa Ntuli said the parties were in dispute over union demands for the permanent employment of contract workers, the provision of HIV/Aids drugs, allowing training to take place during work hours, and four weeks' severance pay for every year of service.
Should Wednesday's negotiations fail, the union would issue a 48-hour strike notice, Ntuli said in a statement.
He said the union was satisfied with the federation's 10.5% wage offer. "What we require is a comprehensive package agreement that will achieve desirable economic outcomes in the industry".
Close to 230 000 workers were ready to embark on an indefinite strike, Ntuli said.
Seifsa was not immediately available for comment.