We propose to analyse 13 coining dies used at the Royal Mint during the 17th century: nine held in the Royal Mint Museum, three in the Museum of London and one in the British Museum. The intention is to shed light on what the dies are made of and how they were made ¿ and what changes took place as a result of the mechanisation of the Mint in the 1650s and 1660s. We will carry out neutron diffraction analyses in order: to determine the martensite, austenite, and the carbon contents of the steel portions; to estimate the phosphorus content of ferrite, if present; and to determine whether or not the dies are composite tools consisting of more than a single piece of metal. We estimate that a total of three days beam-time will be required on ENGIN-X. This proposal forms part of an AHRC-funded PhD project examining technological and organisational change at the Mint between 1600 and 1850.