In 1991, Margaret Miller Gilson, who had led the company since her father's death, passed away, leaving the family-owned business without a clear successor. Remaining family members began to plan for the company's future, and in 1993 it was decided that Miller Electric should form an alliance with Illinois Tool Works (ITW) , a multi-national company based in Chicago.

ITW had much in common with Miller Electric in terms of business philosophy, and in 1992 it had been ranked as one of the top 100 "Most Admired American Corporations" by Fortune magazine. ITW brought to Miller the resource base and global perspective needed to further strengthen the company's position as a world leader in the welding industry.