Metal Bollard Materials

Reliance Foundry's metal Bollards and post covers are cast or fabricated in a variety of high quality metals prior to machining, to produce the optimal Bollard appearance.

Cast Ductile Iron

Many of our ornamental Bollard castings are available in ductile iron. Cast ductile iron (aka 'spheroidal graphite cast iron') is an alloy that is much stronger than standard cast iron; this robust metal is able to withstand the elements and physical abuse that a more brittle cast iron may not. Grey iron was the original "cast iron" or "wrought iron", and is an iron alloy characterized by its relatively high carbon content; this carbon exists as tiny, irregular flakes within the structure of the metal, leading to cast iron's characteristic brittleness. In ductile iron the graphite is in the form of spherical nodules rather than flakes, thus inhibiting the creation of cracks and providing the enhanced ductility that gives the alloy its name.

Steel

Many of our steel Bollards and Bollard covers are fabricated and welded as architectural metalwork highlights. These fabricated versions provide confidence for stand-alone settings, and provide superior strength when used in conjunction with security Bollard installations. Steel is an alloy consisting mostly of iron, with carbon content between 0.2% and 2.1% by weight, depending on the grade. Many other alloying elements are used such as manganese, chromium, vanadium, and tungsten; varying the amount of alloying elements in the steel controls qualities such as the hardness, ductility, and tensile strength of the resulting Steel. Steel with increased carbon content can be made harder and stronger than iron, but is also less ductile.

Cast Aluminum

Many of our decorative Bollards are foundry sand cast in aluminium. This aluminum alloy is a soft, durable, lightweight, malleable, ductile metal with appearance ranging from silvery to dull grey, depending on the surface roughness. Aluminum has about one-third the density and stiffness of steel. It is ductile, and easily machined, cast, drawn and extruded. Corrosion resistance can be excellent due to a thin surface layer of aluminum oxide that forms when the metal is exposed to air, effectively preventing further oxidation.

Stainless Steel

Several of our removable Bollards and bike Bollards are now available in stainless steel. Stainless steel is a steel alloy with a minimum of 11% chromium content by mass. Stainless steel does not stain, corrode, or rust as easily as ordinary steel (it stains less, but it is not stain-proof). It is also called corrosion-resistant steel. There are different grades and surface finishes of stainless steel to suit the environment to which the material will be subjected in its lifetime. Stainless steel is popular to use in architectural metalwork as it helps minimize oxidation or rusting in the toughest elements.