Birmingham Mint presses and six planchet presses for making blanks from strip metal. These were installed at the Bath Street works, and in that year trade tokens were struck for use in Australia. In 1851 coins were struck for Chile using the letter "H" as a mintmark. The same year copper planchets were made for the Royal Mint to make into pennies, halfpennies, farthings, half-farthings and quarter-farthings. In 1852 the Mint won a contract to produce a new series of coins for France. In this the Mint pioneered the minting of bronze. Ralph Heaton III (son of Ralph II) took key workers
Glass-to-metal seal dark. Oxygen-free copper has to be used if the metal comes in contact with hydrogen (e.g. in a hydrogen-filled tube or during handling in the flame). Normally, copper contains small inclusions of copper(I) oxide. Hydrogen diffuses through the metal and reacts with the oxide, reducing it to copper and yielding water. The water molecules however can not diffuse through the metal, are trapped in the location of the inclusion, and cause embrittlement. As copper bonds well to the glass, it is often used for combined glass-metal devices. The ductility of copper can be used for compensation of the thermal expansion