[2] After graduating from the University of Michigan, Kahn began his career as an engineering draftsman for the Union Bridge Company of New York.

In 1900, Kahn moved to Japan for two years, laboring in engineering, construction, and maintenance of iron and sulfur mines.

[6][12][13] Kahn's first assignment was collaborating with key architect Ernest Wilby in Ann Arbor on the University of Michigan's[13] new College of Engineering building.

[13] Kahn and Wilby wanted to use reinforced concrete for the building's floors, in place of traditional wood supports.

[16] During the construction of U.S. War College building in Washington, D.C., he initiated methods improving the then existing technology of reinforced concrete by beginning work developing the Kahn system of steel bars.

[2] Kahn understood the structural challenges inherent in the existing method of concrete reinforcement used at the end of the nineteenth century.

He experimented in his brother's basement, where he developed an improved type of reinforced beam called "the Kahn Bar".

[16] Kahn chose Youngstown in 1907 as the ideal location because the city's proximity to steel production in Mahoning County and reduced shipping costs.

[2] Kahn was the founder of United Steel Company in Wooster, Ohio, and chairman of Truscon Laboratories in Detroit.

[2] Kahn was also a member of the American Society of Civil Engineers, which awarded him The Collingwood Prize for his paper "The Coal Hoists of the Calumet and Hecla Mining Company" in 1889.

[27] The Kahn bar was a straight steel beam whose edges were slightly bent, resulting in improved stress distribution "wings" that increased tension strength.

[25] Additionally he encouraged Truscon employees with financial incentives to develop new and improved ideas to benefit the company.

[25] For example, employee David H. Morgan was financially rewarded for inventing a new type of airplane hangar door, subsequently manufactured by Truscon.

By 1939, Kahn's system was used in 134 U.S. cities and was adopted by builders in Africa, Europe, Canada, China, Brazil, and Mexico.

Both queries came to the conclusion that the Kahn system was not to blame for either faulty design or errors; rather, poor construction techniques were responsible.

Hy-Rib products were also used in the construction of tunnels, conduits, flumes, culverts, silos, cisterns, chimneys, and water tanks.