Guest Keen and Nettlefolds expanded through the acquirement of many companies, and the establishment of numerous subsidiaries, including Guest Keen and Nettlefolds (Midlands) Ltd which was established in 1948 and was made up of The Bolt & Nut Division in Darlaston, Staffordshire and the Screw Division in Smethwick, Birmingham. In the late 1960s the headquarters of Guest, Keen & Nettlefolds Ltd., by then an investment company, adjoined the Heath Street Works, Smethwick, a 50-acre complex run by G.K.N. Screws and Fasteners Ltd. and employing some 4,500 people. G.K.N. had several other subsidiaries in Smethwick: G.K.N. Distributors Ltd. had its headquarters at the London Works, while G.K.N. Group Services Ltd. was in Cranford Street, G.K.N. Reinforcements Ltd. in Alma Street, and G.K.N. Fasteners Corrosion Laboratory in Abberley Street. Smethwick Drop Forgings Ltd. of Rolfe Street, acquired by G.K.N. in 1963, was run as a subsidiary of G.K.N. Forgings Ltd.
