A large increase in the membership of the Society in the 1950s reflected the introduction of a student grade of membership in 1951. In 1968 Associate Members were re-graded to Corporate Members and the new grade of Engineer Associate was introduced. By 1971 total membership of the Society peaked at just over 4000.
An Australian branch of the Society was the first group to establish outside of Britain just before the outbreak of World War II and was inaugurated as a division in 1947. A number of branches were also established in Newcastle-upon-Tyne, Nottingham, Edinburgh and the East of Scotland, Birmingham, Manchester, South Wales and the Bahamas.
Several awards were created by the Society of Engineers including the Churchill Medal. Winners of this medal needed to demonstrate an important contribution to contemporary engineering, an original engineering project or development solely conceived by the nominee and executed under his or her supervision, or project development to which they had made the major engineering contribution. The IET continues to award a Churchill Medal which today recognises a team or individual for outstanding achievements and contributions to engineering and technical advancement in support of military operations.
In 2001 the SoE became a professional affiliate of the Engineering Council in the UK. In 2005 the SoE was absorbed by the Institution of Incorporated Engineers, now the IET.