Comparison of Aluminum & Steel Poles

Flagpoles are one common application of steel and aluminum poles.

Few of us give any attention to the many mundane items that make modern living possible. One example of such an item is the wide variety of aluminum and steel poles that appear everywhere from mechanical components to architecture.

Weight

The density of steel ranges from two to three times that of aluminum, on average. Its weight (for a pole of a given size) is thus correspondingly greater. Aluminum is the preferred material for applications where minimizing the weight of the pole is a priority, one example being the leading-edge spars in the wings of aircraft.

Strength

Steel has significantly higher tensile, compressive and shear strengths than a comparable piece of aluminum. Steel is thus preferred in roles where strength and durability is of greater concern than weight and ease of handling. An example would be the mechanical components in an engine. Aluminum may still be preferred; for instance, cast aluminum is used in addition to steel tube-construction for commercial-grade flagpoles.

Corrosion

Aluminum has higher resistance to weathering and corrosion than steel (with the exception of some specially made corrosion-resistant steels). Aluminum forms a thin layer of aluminum oxide (sapphire) which remains adhered to the metal and stops any further corrosive reaction.

References

• Simetric: Characteristics of Metals