Spring City warrants its ductile iron lamp post and ductile iron bases to be free from defects in materials and workmanship under normal use and operation for 25 years (AASHTO minimum design life for luminaire support structures less than 15 meters). The definition of “normal use” includes damage resulting from motor vehicles traveling at posted speed limits colliding with the lamp post.
Upon receipt of proper notification from the owner, Spring City will replace any lamp post found to be defective or damaged within the warranty period. Spring City shall not be liable or responsible for labor charges or other expenses involved in the removal or disposal of the original product or the installation of the replacement product. Spring City’s liability hereunder is limited to replacing the defective or damaged lamp post.
Why choose ductile iron?
Ductile iron, also called ductile cast iron or nodular temperatures. Magnesium is added to molten cast iron, which cause the graphite in the iron to solidify in round nodules instead the flacks in regular gray iron. Ductile Iron has been successful because it offers a combination of versatility and properties not available in any of its rivals. Its castability, machinability, damping properties, and economy of production are almost equal to those for which Gray Iron is famous, but its mechanical properties - strength, wear resistance, fatigue strength, toughness and ductility are competitive with many cast, forged and fabricated steel components.
The American Association of State Highway and Transportation Officials (AASHTO) are the nationally recognized standards organization for the analysis of lighting structures. They acknowledge the bending strength of ductile iron to be 3 to 4 times that of cast aluminum and grey iron. If your application requires, or may require some time in the future, banner arms, signage, flags or other significant load requirements ductile iron will probably be the only material that will meet the AASHTO wind loading requirements. Please be sure to require the manufacturer of your chosen light standard to supply calculations for your specific application.