"We want the strike to end and are quite hopeful that an agreement can be reached soon," spokesperson Mokgadi Pela told Reuters.
The National Union of Metalworkers of South Africa (Numsa), whose stoppage by over 200 000 members began on Tuesday, rejected a fresh wage offer by employers.
The Steel and Engineering Industries Federation of Southern Africa (Seifsa) tabled a fresh offer of wage increases of up to 10%, up from 8% previously, while Numsa wants hikes of 12 to 15%.
"Regrettably, it would appear that we continue to be miles apart with the union," Seifsa chief executive Kaizer Nyatsumba said in a statement.
Sticking points include Numsa's insistence that the agreement being negotiated only be for one year, while the employers want to lock down a three-year deal.
Meanwhile, US auto giant GM said on Friday it had suspended production at its main South African assembly plant in Port Elizabeth. "The plant has been shut since yesterday because of the parts supplier issues," GM spokesperson Denise van Huyssteen said.
Japanese automaker Toyota said it was unaffected. "We still have full production capacity," Toyota spokesperson Mary Willemse told Reuters.