Low specific weight of aluminum

One of the most crucial properties of aluminum is its specific gravity. With high stability and tensile strength, it weighs only about half of steel with the same strength values. The specific weight is influenced by the respective alloying partners, which usually make the aluminum heavier.

Average weight

The density value of 2,700 kilograms per cubic meter is used as the average specific gravity of a manganese-silicon aluminum alloyed with a total of eight types of metal. This standard material thus develops the following weights in the different construction types:

Rectangular pipes

10 × 10 mm, wall thickness (Ws) 2 mm = 0.173 kg (kg) per running meter (running meter)
20 × 20 mm, Ws 5 mm = 0.813 kg / linear meter
30 × 30 mm, Ws 5 mm = 1.355 kg / running meter

Rectangular solid rods

10 × 10 mm = 0.271 kg / running meter
20 × 20 mm = 1.084 kg / linear meter
30 × 30 mm = 2.449 kg / linear meter

Round pipes

Outer diameter 10 mm x inner diameter 8 mm = 0.136 kg / linear meter
20 × 15 mm = 0.639 kg / running meter
30 × 25 mm = 1.064 kg / linear meter

Round solid bars

Diameter 10 mm = 0.213 kg / linear meter
20 mm = 0.851 kg / linear meter
30 mm = 1.916 kg / running meter

Sheets, plates and ribbons

Area 30 × 30 mm, thickness (S) 5 mm = 0.012 kg (kg) per piece (pcs)
100 × 100 mm, S 5 mm = 0.135 kg / piece
100x100mm, S 10mm = 0.270kg / pcs
300 × 50 mm, S 5 mm = 0.203 kg / piece
300 × 100 mm, S 10 mm = 0.810 kg / piece
10 × 1000 mm, S 5 mm = 0.135 kg / piece

Low density leads to low weight

The density of aluminum is relatively low despite the stability, resulting in the low specific gravity. Steel has about three times the density, which makes a difference in weight of workpieces between twice and three times.

If metal structures are to be mounted with comparable stability of aluminum or stainless steel, the role of the weight decides. Aluminum is used in vehicle and aircraft construction, while stainless steel is preferred in stationary bridge construction or for agricultural machinery.

In addition to the advantages of aluminum due to its low specific gravity, there are some material specific limitations that affect its usability. These include the permanent breaking strength and the possible joining of workpieces by means of welding, where stainless steel has clear processing advantages.

Heavy alloy partners

As already easily apparent in the self-experiment, there are some alloying partners for aluminum, which have a significantly higher specific gravity. They affect the total weight of workpieces partially noticeable. Typical examples are chrome, brass and copper, which lead to a significant increase in weight for each workpiece.

Tips & Tricks

Despite its stability, aluminum has a special property that you should consider when using as a material. The soft metal deforms quickly under mechanical stress, but has no good absorption capacity against the applied force. The non-existent buffer effect loads, for example, movable suspensions such as hinges or attachment points without a damping effect.

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