Why is there Lead in underground brass?
The main reason lead is in brass is to make the brass pressure tight. In the foundry process lead is the last element to solidify and therefore seeks and fills the microscopic voids (porosity) in the brass.
Lead also acts as a lubricant during the machine operation allowing for
easier machining and longer tool life.
Lead also gives brass ductility so that it bends before it breaks.
less...
