How are alloy rims made?
A metal element of a wheel, providing the connection between the hub and the tire, the rims must be strong and resistant to shocks. How are they made and with what materials?
The manufacture of rims
The role of the rims is to support the weight of the tire, which is responsible for rolling the vehicle. So they need to be consistent, firm and hard while being as light as possible. In the past, automakers made them from pressed sheet steel and adorned them with painted plastic bezels. Currently, they are made from steel, aluminum, magnesium or carbon to produce the desired performance. For sports cars, they are made of aluminum. This is a trend gradually adopted by some consumer vehicles. Let’s see the manufacturing process.
The stages of production
The rims are produced in foundry factories working on behalf of car manufacturers. These have the tools needed to cast and melt the material used, including core and cooler racks, molds, finishing tools, and everything in between.
The steel or aluminum ingots used to make the rims are melted one by one at a very high temperature. The metal liquid is then poured into a sort of large basin to facilitate handling. Using a large ladle, take a certain amount and pour it into a mold. Another machine exerts great pressure on it so as to make the rim perfectly compact and not to leave any traces of air bubbles. Once this mold has cooled, it is opened to take out the rim still in its raw state. It is polished and shiny, and metal residues are removed for a smooth product to the touch. It then undergoes a whole series of tests, including rotation and impact testing, to ensure its strength when the tire is installed. Next comes the sheer test followed by the balancing and dimension control test. The latter is used to check if the size, the perimeter, the diameter and other measurements correspond to that of its category. The painting is done last with a machine and the finishing touches are done by hand to ensure its shine. A final quality control precedes the packing of the product.
The various types and qualities of existing rims
Steel or sheet rims are the most widely used, therefore sold on the market. Entry-level vehicles and utility vehicles are the fondest of them, but they are also useful for fitting winter tires. There are also aluminum rims previously reserved for sports vehicles, as they are light, but now they are accessible to mainstream cars. Strong demand for aluminum rims has enabled specialist retailers to offer an attractive price / quality ratio. The last type and not the least is the composite rim or alloy of magnesium and carbon. It is dedicated to car competitions or to series upgrades of high-end sports vehicles. Very light, it reduces the weight of the suspended masses of a vehicle and considerably improves performance.