John was also heavily involved in a study of the relations of surfaces generated in the machining process to the mechanical properties of structural components. In 1964 he and his colleague Michael Field coined the term "surface integrity" and applied it to this subject, which has since been used as a quality standard around the world.
John became vice-president of Metcut in 1958 and senior vice-president from 1978 to his retirement in 1990. He was a prolific author and contributor to metallurgical and manufacturing literature. He wrote about one hundred papers. He also was heavily involved in educational and engineering committees and societies at both the local and the national levels. He was a member of Phi Lamba Epsilon, Tau Beta Pi, Sigma Xi, and Alpha Sigma Mu. He was awarded many honors, including the William Hunt Eisenman Award from the American Society of Metals International, Cincinnati Chapter; the Joseph Whitworth Prize from the Institution of Mechanical Engineers, London, England; fellow, American Society for Metals; Engineer of the Year, Technical and Scientific Societies Council of Cincinnati; Distinguished Alumnus Award, University of Cincinnati; and the Research Medal, Society of Manufacturing Engineers. He was elected to the National Academy of Engineering in 1984.
John Kahles was above all a generous and friendly person. He was a strong family-oriented individual. He and his wife, Bea, had seven children and fourteen grandchildren. His house was always filled with his children and innumerable neighbors and friends. He had a 160-acre retreat in Blind River, Canada, where he and his family had vacationed each summer for thirty-five years.