Approximately 220 United Steelworkers (USW) members began a strike against aerospace industry supplier Carley Foundry in Blaine, Minnesota, on Saturday.
USW District 11 Director Emil Ramirez accused Carley's management of dividing union members by proposing a lower wage tier for new employees among other contract changes.
"Carley has broken federal labor laws in its drive to force workers to accept its unfair and unnecessarily concessionary proposals, and we are standing up to demand the fair contract USW members have earned," Ramirez said in a statement. "As one, we will deliver the message to management that our work has dignity and we deserve the company's respect."
The members on strike are part of Local 63B.
The USW represents roughly 850,000 workers in the metals, mining, rubber and other industries.
FOX Business' inquiry to Carley Foundry was not returned at the time of publication.