The most common materials used for fire hydrants are:
Cast iron
Cast iron is a very popular material for fire hydrants due to its durability and corrosion resistance. Cast iron hydrants can last 70 years or more. The main downside is that cast iron is heavy and can break more easily on impact.
Ductile iron
Ductile iron is a modified form of cast iron that provides more strength and impact resistance. Ductile iron hydrants offer similar durability to cast iron but at a lower weight and lower cost. They can last 50-60 years.
Stainless steel
Stainless steel hydrants provide excellent corrosion and impact resistance. They typically last 40-50 years or more. However, stainless steel is significantly more expensive than cast iron or ductile iron. Stainless steel hydrants are often used in coastal areas or where corrosive soils are present.
Copper
Copper fire hydrants are also very corrosion resistant and long-lasting, with a typical service life of 40-50 years. Like stainless steel, copper hydrants are more expensive. Copper may also be subject to theft since it has resale value. Copper hydrants work well in coastal or industrial areas.
Composite
Newer composite hydrants made from materials like fiberglass or polycarbonate plastic provide lightweight, corrosion-proof options. Composite hydrants typically last 25-40 years. They are more expensive than conventional materials but cheaper than stainless steel or copper. Composites work well where corrosive or reactive soils are present.
Concrete
Concrete fire hydrants encase working parts in concrete for corrosion protection. They typically provide 30-50 years of service. Concrete hydrants are inexpensive but very heavy. They are not commonly used except in some rural or low-income areas.
The most popular fire hydrant for sale and cost-effective materials are cast iron, ductile iron, and stainless steel due to their durability and corrosion resistance. Copper and composite hydrants are good for harsh, corrosive environments despite their higher upfront cost.