Crosby Garrett Helmet some point the helmet was repaired using a bronze sheet which was riveted across two splits. Only two other Roman helmets complete with visors have been found in Britain – the Newstead Helmet and Ribchester Helmet. The helmet and visor were cast from an alloy consisting of an average of 82% copper, 10% zinc and 8% tin. This alloy was probably derived from melted-down scrap brass with a low zinc content, with which some tin had been added to improve the quality of the casting. Some of the fragments show traces of a white metal coating, indicating that the visor
Beryllium copper powdered steel or iron seats & guides. The softer BeCu reduces valve wear and increases valve life. Beryllium copper (C17200 & C17300) is an age-hardening alloy which attains the highest strength of any copper base alloy. It may be age hardened after forming into springs, intricate forms or complex shapes. It is valued for spring properties, corrosion resistance, stability, conductivity, and low creep. Tempered beryllium copper is C17200 & C17300 that has been age hardened and cold drawn. No further heat treatment is necessary beyond a possible light stress relief. It is sufficiently ductile to wind on its own diameter