Nearly 900 steel workers from BlueScope's New Zealand operations will go on strike for a second time in 24 hours tomorrow.
The protests follow six months of stalled pay talks, and what union members believe to be low-ball pay offers from BlueScope.
Joe Gallagher, E tū union industry co-ordinator, said BlueScope refuses to budge on their offer.
"While our Government is committed to lifting wages, internationally employers are co-ordinating a strategy to hold wages down," Gallagher said.
"There is a clear and growing trend of top multi-national companies presenting low pay offers, despite big profits. We're seeing this in the mining sector, with the low-ball offer to our members at OceanaGold, and other sectors are sending the same message."
BlueScope's New Zealand companies posted a profit of A$1.6 billion ($1.7b) this year – lifting earnings by 80 per cent.
At NZ Steel, workers received a pay rise of just one per cent over the past two years while also giving up their bonuses, a move that saved BlueScope millions of dollars.
"Fair's fair," Gallagher said. "It's time to give back to the workers who took a hit when times were tough."
"This is hot, dirty and hazardous work and yes, our members get paid for that. But this is a dispute about a company that's delivered an eye-watering profit and thinking it's okay to offer a mean-spirited pay rise to its highly skilled steel workers. It isn't."
The strike affects about 120 members at BlueScope Pacific Steel's rolling mill and wire mill, and about 750 members from BlueScope's NZ Steel mill at Glenbrook.