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|THE MANUFACTURE OF STREET FURNITURE - PUBLIC BENCH|
|V. Ryan © 2011|
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Study the animation of the bench shown below.
|Name a specific metal which could be used in the manufacture of the bench.|
|Mild Steel Round Section Tube|
|Explain why you have chosen the metal named above. You may wish to consider the following key words / phrases:|
|CORROSION RESISTANCE - ROUND SECTION TUBE
- LIGHT WEIGHT
STRONG AND STURDY - NUMEROUS SUPPLIERS - PHYSICAL PROPERTIES - STRENGTH - TENSILE STRENGTH - DUCTILITY - MALLEABLE - PAINT - PLASTIC COATING - GALVANISED - MANUFACTURING PROCESSES - COST - MACHINE-ABILITY - WELDING
|Mild steel tube is ideal for the manufacture of the
bench. It is relatively light weight and yet sturdy, making it ideal for
the manufacture of street furniture. Mild steel tube is available from
numerous suppliers and can be shaped and formed into almost any shape.
Tube has been selected as the ‘section’, because its shape/structure adds strength to the existing physical properties outlined below. Mild steel tube is much lighter than a solid section mild steel, making the bench easier to manufacture and transport.
Mild steel has a range of suitable physical properties. Mild steel tube possesses great ‘strength’. It withstands forces being applied to it and will not break, shatter or deform, even when under torsion or tensile stresses. It has the ability to absorb force and flex in different directions. Street furniture is often ‘abused’ and vandalised, steel is highly resistant to such treatment. Ductility and tensile strength, are other physical properties of steel. When being manufactured, the steel tube will be shaped and stretched, into the arches and curves (seen in the photographs). Steel is malleable when heated to high temperatures. At ‘red heat’, it can be reshaped in all directions without cracking. A material without these properties would simple break or shatter. The surface of steel is ‘tough’ and ‘hard’, withstanding everyday blows, knocks and scratches experienced by street furniture.
Mild Steel can be coated / finished in a variety of ways including painting, plastic coating and galvanising. This means that benches can be manufactured with ‘finishes’ to suit the customer. Each of these finishes will prevent corrosion and lead to a longer working life for the bench. Without the application of one of these finishes, the bench would rust very quickly and soon become unusable.
Mild Steel is relatively cheap compared to quality natural woods and other metals. As a result, the batch manufacture of steel tube benches is cost effective. An equivalent aluminum bench would be more expensive, more difficult to manufacture and be less likely to stand up to everyday use. Non-ferrous metals such as copper and brass do not exhibit the physical properties as steel and their extremely high price excludes them from consideration.
Mild steel tube possesses all the physical properties to withstand the manufacturing processes required to make a bench of this type. It can be formed with pipe benders and in jigs. It can be shaped relatively easily when heated to ‘red’ heat. It can be cut and shaped with general workshop tools and equipment. It can be machined on lathes a milling machines. Furthermore, it can be welded through electric arc, mig welding and it can be brazed with an oxy-acetylene torch.
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