Halvor Olsen Hem was born August 14, 1863, in Saude, Norway, to Ole and Aste Hem.  H.O. Hem was born into a family of engineers and mechanics, and before the age of fifteen had designed numerous mechanical devices including scales, steam engines, and sewing machines.  In 1882, H.O. Hem came to the United States where he became an engineer with the H.N. Strait Manufacturing Company of Kansas City, Missouri.  It was in 1890 when he became the chief engineer, superintendent and vice-president of the company.  H.N. Strait Manufacturing Co. produced scales under the name Monarch for twelve years under H.O. Hem.  In 1902 the company was sold to Fairbanks, Morse and Company where H.O. Hem created a complete line of scales. H.O. Hem remained there until 1915 when he became a consultant to the Toledo Scale Company, and in 1928 he became the chief engineer of Toledo Scale.  Some of his developments in scales were in the area of heavy capacity, mechanical devices for World War I and II, wind tunnel measuring systems, and the automobile industry.

During his tenure as an engineer, H.O. Hem received various awards and honors.  He received the John Price Wetherill medal in 1932 for his perfection of pendulum scales.  In 1936 he received an honorary Doctor of Science degree from the University of Toledo.  H.O. Hem was also part of many associations and organizations.  One such group was the Yards and Terminals Committee 14 of the American Railway Engineering Association, which determined the rules and regulations for scales and their installation.  He was also a member of the American Society of Civil Engineers, American Society of Mechanical Engineers, American Railway Engineering Association, and the National Scale Men’s Association.

H.O. Hem retired from the Toledo Scale Company in 1947, but he still helped the company as a consultant.  H.O. Hem was married twice, first to Lillian with whom he had two children, H. Warren and Verona, and second to Helen Vaughan.  He died on November 11, 1952.