Harold McMaster was born in Deshler, Ohio (approximately one hour south of Toledo) in 1916 on a tenant farm. He was one of 13 children. He earned a scholarship to Defiance College and later transferred to Ohio State University where he earned degrees in arts, nuclear physics, astronomy, and mathematics.
During WWII he worked for Libbey-Owens Ford (LOF). In 1948 he left LOF to start Permaglass. In 1969 Permaglass merged with Guardian Industries and in 1971 McMaster left the company. Later in 1971 McMaster became a co-founder of Glasstech which manufactured tempered glass. The company struggled in the 1990s and declared bankruptcy in 2002.
McMaster was inducted into the Ohio Science Hall of Fame in 1991. He is considered a pioneer in the commercial use of solar energy. McMaster held over 100 patents related to glass bending and tempering, solar energy, and rotary engines. He and his wife Helen have given millions of dollars to various NW Ohio institutions including the University of Toledo, Bowling Green State University , Defiance College and the Toledo-Lucas County Public Library. McMaster died in 2003 at the age of 87.