Many utility and control-cabinet keys are made from one piece of solid metal. Others have metal heads and plastic bodies.
The metal parts of utility and control-cabinet keys are made from either a zinc alloy or steel. The plastic parts are made from a thermoplastic, sometimes reinforced with fibreglass.
Zinc alloy
Most utility and control-cabinet keys are made from die-cast zinc alloy. In order to die-cast zinc (see {{widget type=”cms/widget_page_link” anchor_text=”How are utility and control-cabinet keys manufactured?” title=”See How are utility and control-cabinet keys manufactured?” template=”cms/widget/link/link_block.phtml” page_id=”3367″}}), other metals need to be added to ensure a high quality of finished product. When chemical elements are added together like this it is called an ‘alloy.’
Aluminium is added to zinc (no more than 4% of the final mixture) which decreases the chance of the metal getting stuck to the inside of the mould and also helps to prevent the zinc reacting with the iron in the mould.
Copper is also added to the mix (no more than 1.25% of the final mixture). It increases the alloy’s strength and hardness.
Steel
Steel is an alloy of mainly iron and carbon. Different amounts of chromium, silicon, nickel, carbon, nitrogen and manganese are added to the iron to change how it can be used.
Some utility and control-cabinet keys are made from ‘chrome vanadium steel.’ Chromium and vanadium are metal elements that are added to steel to increase the metal’s strength. Chromium also increases the steel’s resistance to rusting.
The overall chromium content of steel is usually between 12% and 20% while the overall content of vanadium is between 0.2% and 1%.
Vanadium is expensive so cheaper ‘chrome vanadium’ steel products often have a very low vanadium content, as low as 0.1%.
Thermoplastic
Thermoplastic is a plastic that can be repeatedly melted to a liquid and cooled to a solid.
The most common thermoplastics used are polypropylene, polyurethane, polycarbonate and acrylic. Thermoplastics are used to make a huge variety of objects in the modern world.
Plastic is durable, although not as strong as metals, comfortable to use and looks pleasing to the eye.
Fibre-reinforced plastic
Fibre-reinforced plastic (FRP) is very occasionally used to make utility and control-cabinet key bodies. It is a plastic with strands or fibres of a reinforcing material running through it. Glass is the most common type of fibre to be used but they can also be made from carbon, basalt (a volcanic rock) or synthetic fibres such as aramid. Glass-reinforced plastic (GRP) is commonly known as ‘fibreglass.’
Fibre-reinforced plastic is strong and lasts for a long time.
