With the expansion of the electronic industry and its demand for magne c materials, Robert M. Arnold, in 1940, moved the opera on back to Marengo to be nearer the Chicago market. During the early part of World War II, The Arnold Engineering Company manufactured parts for the Sherman and M-3 tanks. As the war progressed, Alnico magnets were also produced for one of the largest O.S.S. government contracts of its kind in the war. Proximity fuse magnet assemblies were manufactured for motor and an -aircra shells, in appropriate top clearance. In 1946, Allegheny Ludlum Steel Corpora on purchased all the stock of The Arnold Engineering Company. At that me, The Arnold Engineering Company became a wholly owned subsidiary opera on. Robert M. Arnold con nued as President of the company and in addi on, became a Vice President and Director of Allegheny Ludlum. Un l 1948, the principal product was Cast Alnico permanent magnets. They ranged in size from large cas ng assemblies weighing over two tons to very small components weighing less than one gram, and are used in motors, magne c ore separators, medical and home appliances, and in many electronic devices such as microphone components in N.A.S.A. communica on equipment. In 1948, a new product line was introduced. This line was called Mo-Permalloy powder cores and was originally manufactured under license agreement with the Western Electric Company. They are used primarily in electronic loading devices, electrical ļ¬lters, and telephone equipment. R H A B P 4 Early Powder Core Products Manufacturing