In 1874 he became a foreman for Singer Sewing Machine Co., then was employed by Colt's Patent Firearms Manufacturing Co., later went to Winchester Repeating Arms Co., and then was Superintendent and Treasurer for the Sharps Rifle Co. on June 1, 1876.

[1] After the dissolution of the Sharps Rifle Co. in 1881, Borchardt returned to Budapest, where he was employed by Fegyver és Gépgyár Részvénytársaság and by 1890 gained the position of works director.

His return in Europe was interrupted by a short stay (1890–92) in the United States as a consultant to Remington Arms in relation to the development of the Lee rifle for the U.S. Army trials.

[2] By 1893 Borchardt had an association with Ludwig Löwe & Company of Berlin, Germany, a manufacturer of machine tools, to produce the C-93, a semi-automatic pistol that he had invented based upon the Maxim toggle-lock principle.

Hugo Borchardt had many non-firearms patents: a rock drill, a shirt-neck shaper, gas burners, ball-bearings, a wire-straightener, and various electrical apparatus.