AbstractThe manufacture of solid diamond fibres by chemical vapour deposition onto various wire and ceramic cores and the production of hollow diamond fibres by removal of the cores is described. The values for Young's modulus of diamond fibres and diamond fibre–Ti alloy metal matrix composites calculated via the rule of mixtures are predicted to be substantially higher than for the corresponding values for the commerical SiC fibre products. It is concluded that chemical vapour deposition diamond fibres offer, for the first time, the possibility of exploiting the properties of diamond in engineering structures.MST/3007