Bronze is an alloy that contains mostly copper, tin and some lead . It’s introduction over 5,000 years ago revolutionized metal work and launched the Bronze Age. By adding tin to copper, workers created a metal that was stronger and impervious to corrosion. Bronze artifacts have been found dating from as early as 3,500 BC.
How is Bronze gate hardware different from Brass gate hardware?
Brass is also an alloy of copper, but differs from bronze in that its primary additive is zinc instead of tin. Brass is similar to bronze in hardness but suffers from the process of ‘dezincification’. This process that begins upon exposure to heat and humidity is the leaching of zinc from the metal. As the zinc migrates from the copper it leaves a porous structure susceptible to cracking and corrosion. As a result, brass hardware may eventually exhibit persistent red spots (zinc oxide) and become more brittle and crack as they age.
Brass is commonly used for door hardware because the melting temperature is lower than bronze making it easier to cast in an automated production. The high melting point of bronze necessitates casting in sand (a more difficult process) since the metal molds used in brass production would melt. A new sand mold is created for every individual casted part for Coastal Bronze.