When buying wheels, multiple factors are taken into consideration, like material, weight, appearance, etc. Yet one thing goes unseen when buying wheels- the manufacturing process. Manufacturing process determines the quality and the price of alloy wheels. The product quality and required production cost are different in all the processes. Below are mentioned all the processes, and how they affect the price and quality of wheels.
Manufacturing Processes:
- Casting:
In this process, molten aluminium is poured into the mould to form an alloy wheel. It is the most common type of process used in manufacturing single-piece wheels. Casting is further divided into two categories:
- Gravity Casting:
In this process, molten aluminium is poured into the mould, and no external pressure is applied to fill the mould, except the omnipresent gravity. Since this method relies on gravity to fill the mould, aluminium isn’t densely packed in the mould. Because of this, to achieve good strength, gravity cast alloy wheels need to be heavy. Production cost isn’t high in this process, which makes gravity cast alloy wheels cheaper than the rest.
- Low-Pressure Casting:
The process is similar to gravity casting with a slight difference of additional positive pressure applied. Molten aluminium is packed more densely compared to gravity casting. Alloy wheels made from this process are stronger and expensive than the gravity cast alloy wheels UK.
- Spun Rim Or Rim Rolling Technology:
This specific process starts with a low-pressure type of casting and uses a unique machine that spins the casting, warms the external part of the casting and afterwards by the help of steel rollers squeezed against the edge zone to pull the rim to its last width and shape. The strength of alloy wheels formed with this process is almost equal in strength to forged alloy wheels UK. This process is also used in the manufacturing of racing wheels for Formula One.
- Forging:
In this process, a solid block of aluminium is compressed between forging dies (a tool for shaping and cutting). The product formed by this is highly dense and strong. Thus, alloy wheels formed by this process superior in quality and light in weight. The production cost of forging is high, because of which their value in the aftermarket is also high.
Multi-Piece Wheels:
Single piece wheels are made by using any one of the above-mentioned processes. However, the multiple-piece wheels have more than one component, all of which are manufactured separately. For example, three-piece wheels are made up of an assembly of three pieces, centre, spun aluminium outer barrel (the lip) and spun aluminium inner barrel. Center sections of multi-piece wheels are generally manufactured by the method of forging to provide them with maximum strength.
The barrel or rim sections of these wheels are generally made by the process of the spun rim because it offers the ability to custom-tailor wheels for special applications, which cannot be done in other processes. In a two-piece wheel, nothing is different than three-piece wheels, except the barrel section isn’t divided into two, which leaves only two pieces, centre and barrel. There are also high-end two-piece Toyota NL alloy wheels, in which both pieces are made by forging. This makes them tremendously expensive, hence produced in small volumes.