Workers at Caterpillar’s Joliet, Ill., plant, which manufactures hydraulic systems for some of its large machines, walked off the line Tuesday morning as their contract expired.
Leaders of Lodge 851 of the International Association of Machinists and Aerospace Workers have told local news sources that 94 percent of its membership have honored the strike. The union says the new contract freezes wages for six years and doubles employees' health care costs.
Caterpillar has said the plant would continue to operate and meet production levels.
Neither side has immediate plans to return to the bargaining table.