Mining in Cornwall and Devon tin was found as alluvial deposits of cassiterite in the gravels of stream beds. Eventually tin was mined underground; underground mines sprang up as early as the 16th century. Tin lodes were also found in outcroppings of cliffs. Tin is one of the earliest metals to have been exploited in Britain. Chalcolithic metal workers discovered that by putting a small proportion of tin (5 – 20%) in molten copper, the alloy bronze was produced. The alloy is harder than copper. The oldest production of tin-bronze is in Turkey about 3500 BC, but exploitation of the tin resources in Britain is
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