National Union of Metalworkers of South Africa (Numsa) will stage a national strike in the country's engineering sector from October 5 after wage talks reached a deadlock, the union said on Tuesday.

Employers in the important economic sector, which has struggled amid an economic downturn exacerbated by the Covid-19 pandemic, have baulked at Numsa's demands for an 8% rise in the first year and inflation plus 2% for the following two years.

Industry body, Seifsa, which is offering a 4.4% hike for 2021, inflation plus 0.5% in 2022 and inflation plus 1% in the third year confirmed the deadlock and strike call with Reuters.

"We will launch the strike with a national march," Numsa said in a statement.

Numsa is the largest trade union in the engineering sector and has hit a deadlock with the four big employer associations in the Engineering Bargaining Council, which represents around 430 000 workers in 90 000 companies around South Africa.

The Steel and Engineering Industries Federation of SA (Seifsa) said strike action would have significant impact on the struggling economy and companies.

"We have experienced unprecedented job losses and companies are really struggling to keep their doors open," said Lucio Trentini, chief executive of Seifsa.