Martin, or Mr. Kinnavy as he was known among co-workers, was a pioneer of the tension leveling process, which he developed early in his career at what was then Herr-Voss Corp. In 1971, he received a U.S. patent for the process, which he described simply at the time as "methods for permanently elongating strip." Patents in 11 other countries would follow. 

Even after a half-century, it remains the gold standard for strip leveling in the cold-rolled steel and aluminum sectors, according to the company.  

Mr. Kinnavy also was influential in roller leveling technology and was a major contributor to the development of ANDRITZ’s Strand Extensioner brand of coil slitting lines. 

While at Herr-Voss, which was acquired by ANDRITZ  in 2014, Mr. Kinnavy served as vice president of engineering. Although he retired at the age of 79, he continued to work in the industry as a consultant for nearly two additional decades, sharing his unrivaled knowledge of what was, for him, his “hobby” of tension leveling.

Born and raised in Chicago, Mr. Kinnavy was a veteran of World War II, having served in the U.S. Army as an officer in charge of a military hospital in Iceland. He also developed an engineering solution to a problematic vibration of guns on warplanes. 

He held a master’s degree in mechanical engineering from Illinois Institute of Technology, where he also completed doctoral studies.

In 1966, he moved to Warren, Ohio, where he and his wife, Nancy, raised their family.  

“Martin was always very respected by those that were fortunate enough to work with him in the office as well as those that he worked with in the industry. Always the quintessential gentleman, those who knew him came to appreciate his kindness, generosity and never-failing sense of humor,” friends and family said. 

Mr. Kinnavy was preceded in death by his wife, Nancy; his daughter, Nancy; daughter-in-law, Daiva; and his six younger siblings. He is survived by his four children: Daniel, Katherine, Martin (Patty) and Noreen; grandchildren Martin, Katy, Andrew and Connor; a great-grandchild, Fiona; and his sister-in-law, Joan.