The problem of choosing between steel and alloy wheels continues to cause a lot of controversy among motorists. Manufacturers add fuel to the fire by advertising products in every possible way own production for the purpose of sale. Therefore, stereotypes have formed about the characteristics of products made from different metals that do not correspond to reality. Hence the purpose of this material is to tell how stamped, forged and alloy wheels how to distinguish them from each other and which ones are better suited for different operating conditions of a car.
Light alloy wheels
The name "light-alloy" was given to these products because of the properties of the materials from which they are made. This is an alloy of light metals - aluminum and magnesium, for strength and ductility, titanium and copper are added to it in small quantities. Hence the second name of such discs - titanium. There are 2 types of light alloy rims:
- cast;
- forged (pressed).
These 2 groups of products differ from each other in manufacturing technology, performance properties and cost. To understand which of them is better, you need to consider the production of discs in more detail.
Note. Sales representatives often impose on motorists the opinion that, unlike cast products, forged rims are made from incredibly strong and expensive metals, almost from platinum. In fact, this is a myth, the composition of the alloy for the manufacture of both groups of products is exactly the same. Manufacturers can slightly change the ratio of basic and additional metals in the melt at their discretion.
About production technology
As the name implies, cast products are made by pouring molten metal into special molds (casting method). The sequence of technological operations looks like this:
- Metals - the ingredients are placed in a furnace, melted and mixed.
- The alloy is fed to the mold and poured into it with a special ladle.
- After hardening, the workpiece is removed from the mold and moved to machining. At the same time, the structure of the rim and spokes is already formed, it remains only to remove excess material along the edges and refine the holes for the bolts, as well as balance the disc.
- The last stage is testing under certain speed and shock loads.
Reference. In factories famous brands the process is in full automatic mode using CNC machines, even casting is performed by a robot. Manual labor is practically excluded.
The name "forged" does not quite accurately reflect the method of production of these discs, since they are not forged, but squeezed out of a heated alloy on high-power hydraulic presses. The manufacturing algorithm is as follows:
- As in the previous case, an alloy is prepared in the furnace, from which cylindrical blanks are cast.
- Each blank goes through several pressing operations, where it is formed into a solid wheel rim without spokes and holes.
- Products undergo 2 heat treatment operations - hardening (strengthens the alloy) and tempering to relieve internal stresses in the metal.
- With the help of machining on various machines, holes are made in the disks, the spoke pattern is cut out, excess material is removed along the edges and balancing is carried out.
- Testing is carried out on special equipment under critical loads.
Note. So the second myth has been dispelled - that due to the manufacturing technology, forged wheels cannot boast of a diverse design. On CNC milling machines, any, even the most complex pattern, can be cut into the body of the workpiece.
Pros and cons of cast products
The main advantage of cast alloy wheels is the attractive appearance, thanks to which a car of any age and brand looks much prettier. And the choice of products in terms of configuration and number of spokes is incredibly wide. This is the main reason that encourages car enthusiasts to change steel wheel rims to light alloy ones.
Other advantages also matter, but they are technical in nature:
- reduced mass of products gives less fuel consumption and increases the controllability of the car;
- for the same reason, the acceleration dynamics of the car improves, and braking distances- is reduced;
- products are initially balanced due to production technology;
- long service life.
Of the listed positive points, only durability and balance are really noticeable. alloy wheels when the owner of a car changes tires in a tire shop. Improvement in handling and acceleration dynamics can only be felt by an experienced driver, and the change in fuel consumption is so insignificant that it is not noticeable at all (0.1-0.2 liters per 100 kilometers). So beauty is the priority. alloy wheels, and only then their technical parameters are valued.
Now for the disadvantages:
- Products are afraid of strong and sharp blows. A crack appears in the thinnest place or where an air shell has formed inside the metal. Manufacturers claim that the casting cannot be repaired.
- The price of the product is higher than that of stamped steel discs. Due to the difference in prices, the difference can be from 50 to 200%.
- Cast rims should not be used on vans and light trucks as they are not designed for such loads.
- Maintenance operations for such products at a tire fitting (tire change, balancing) are more expensive.
Reference. In the countries of the post-Soviet space, there are many workshops where specialists have got used to soldering cracks in aluminum castings. But such a repair cannot be called complete, and restored disks must not be placed on the front axle of the car.
Advantages and disadvantages of forged wheels
The essential and only drawback of forged rims is the high cost, exceeding casting by 2-5 times, depending on the manufacturer. But for this money you will receive such advantages:
- reliability and durability;
- durability, the pressed rim will last as long as the car itself;
- low weight of the product (even compared to casting), which improves the behavior of the car on the road and reduces fuel consumption.
Thanks to pressing and hardening in the manufacture of such rims, the metal does not have hidden shells and acquires increased strength, so impact cracks are extremely rare. In addition, the spokes of the product can be made thinner and more openwork, giving the wheel design additional lightness and beauty. That's what you pay money for when you buy a forged wheel.
How alloy wheels are made - video
Stamped steel rims - the secret of popularity
More than 60% of all cars in the territory of the post-Soviet countries are equipped with disks made of carbon steel sheet. The vast majority of these machines are equipped with such wheels from the factory, since they are cheaper than others. Exceptions are cars in the “luxury” configuration or elite brands for which “stamping” frankly does not fit in appearance.
Despite the low cost, iron discs have many advantages:
- compared to aluminum alloy, steel has ductility and elasticity, so the rim partially absorbs shocks when driving over large irregularities;
- for the same reason, steel products are easy to repair - deformed places can be straightened, and cracks can be welded;
- scope - transport of any purpose and carrying capacity;
- low prices for wheel maintenance;
- there are no problems with fastening the wheels, for which factory (regular) bolts are used.
The most valuable advantage when driving on our roads is the high repairability of stamped discs and the ability to absorb shocks. Combined with low cost, these features make traditional iron rims the most attractive in the eyes of ordinary users. To understand how their cost is formed, it does not hurt to get acquainted with the manufacturing technology of such products.
Production by stamping
For the manufacture of iron rims, thick sheet steel is used. Workpieces of two types are cut from it - a circle and a strip, sent for further processing. The process looks like this:
- On a hydraulic press, the core of the future disk with bolt holes and technological openings is stamped from a steel circle.
- The strip is sent to the rollers, where it is bent into the shape of a cylinder. The ends of the sheet are welded together, after which the seam is cleaned.
- A hydraulic press squeezes the finished rim out of the cylinder, then a hole for the valve is drilled in it.
- Both elements are connected by welding, then covered with primer and painted.
In the manufacture of stamped products, expensive CNC machines and furnaces are not used, which is why energy costs are significantly lower. Hence the low price of the final product.
Video of the stamping assembly process
Weaknesses of steel wheels
Compared to attractive lightweight aluminum alloy products, forged iron rims lose in appearance, which is often the reason for replacing them. Plastic decorative caps, which are always lost on the potholes of our roads, do not solve the issue, and the owner of the car has to buy new ones.
For reference. To prevent the caps from flying off the wheels, many drivers fasten them to the disks with plastic wiring clamps. This helps, although it somewhat spoils the appearance of the car.
There are other negative aspects in the operation of "stampings":
- due to the large weight of the wheels, the controllability of the machine is worse, and fuel consumption is higher;
- increased stopping distance;
- stamped iron products cannot boast of good balance;
- metal rusts, and therefore requires care.
Judging by the statistics, the listed shortcomings do not bother most Russian drivers too much. Again, some of the negative points are misinterpreted by sellers. For example, the assertion that steel can rot in 2 years and the disk will become unsuitable for further use is unfounded. To bring the metal to such a state, it will take a period twice as long, and with timely care, the product will last no less than light alloy.
Note. There is a myth that the paint of stamped rims is easily scratched and quickly deteriorates, and the light alloy surface cannot be damaged. The second part of the statement is incorrect, alloy wheels can also be scratched, but it is much more difficult to paint them.
Type selection rims it is better to fulfill according to three criteria:
- depending on the operating conditions of the machine;
- class and brand of car;
- active driving in the cold or warm season.
Advice. If you expect to use one set of rims all year round, then taking into account Russian road conditions it is better not to risk money and put a steel "stamping".
The ideal option is to have 2 sets of discs, using them in the warm and cold seasons. For summer ride on asphalt surfaces, light-alloy rims are perfect, but for the winter you need to put stamped ones. The problem is ice that appears on the pavement due to unremoved snow, which is why a flat road is covered with continuous potholes. The same frost along the edges of the roadway will easily scratch your beautiful titanium wheels when leaving the side of the road or approaching close to the curb.
When choosing a set of new disks, it does not hurt to take into account other recommendations:
- It is not worth shelling out and buying light alloy products if you are driving through the fields in an SUV. And vice versa, elite cars operated on flat roads should not be stamped, it looks reprehensible.
- Forged wheels are suitable for any passenger cars and various driving conditions, except for outright off-road.
- Don't try to put light alloy rims on a minivan that is in commercial service, you risk ruining them quickly.
When choosing forged products, a natural question arises - how to distinguish them from casting with external similarity. After all, an unscrupulous seller can slip you a cheaper product at the price of forged wheels. There are some tips for this:
- Forging is easier than casting. For example, a 15-inch forged rim weighs no more than 5 kg, and a cast rim weighs 7-8 kg.
- On pressed products processed by milling machines, you will not find burrs or small flash along the edges, as is the case with casting.
- As a rule, inscriptions on alloy wheels protrude above the surface, and on forging they are deepened, because they are applied by extrusion.
- If the product is branded and is accompanied by documents, then in the forged rim specification you will find the corresponding English word- FORGED.
Advice. There are many exceptions to these rules, which appear when studying the products of domestic or Chinese manufacturers. The best way- buy forged rims at retail outlets with an impeccable reputation or from authorized dealers.
Despite the numerous advantages of light alloy wheels, they cannot win even half of the Russian market. A similar situation is observed in the countries of the former USSR, where stamped products are more relevant and more practical than aluminum ones. A change in trend should not be expected until there is a dramatic improvement in paved roads.
So, you want to change the wheels on your car and buy new or used instead of stock. But how to choose the right alloy wheels for a car if you have never done this before? How do you make sure they fit your car exactly? Believe me, the process of selecting wheels can be much more complicated than just knowing the radius of your wheels.
And the very first piece of advice could be this: it is true that many reputable tire salesmen will know all this information specifically for your car and will play a primary role in right choice cast discs. But there is one logical conclusion here: how do you know that the seller is really knowledgeable and competent in the selection of disks, if you yourself are not competent in this matter - how will you check this? But believe me, choosing a good seller is easier than learning how to choose good ones. suitable discs. It's always better than being able to discuss things like wheel offset, wheel bolt head angle, and so on. But there is another problem: the seller is a person of interest, and his interest, as a rule, lies in the sale of the most expensive disks and the least in demand. It is good if the focus on the buyer and the ideal satisfaction of his needs are higher than his interests for the seller, but this situation is far from always observed. Of course, reviews and opinions of friends and acquaintances will help you choose the right seller of disks. And we go further in the matter of choosing alloy wheels and talk about technical specifications these.
Cast or stamped wheels?
First of all, make sure you really want alloy wheels, not stamped steel ones. The differences between aluminum alloy and steel wheels are huge and it ultimately depends on what you as a driver want from your wheels. And the cons of alloy wheels in front of steel ones are enough. We will not fully compare them in this article, but we will list the main disadvantages of alloy wheels:
- Alloy wheels are more expensive when buying (about 2-3 times).
- Alloy wheels are more expensive to repair and, which is important with the quality of our roads.
- Cast discs are much stiffer than steel ones, which determines what exactly can be damaged if it hits a pit, a pothole or when driving along high-projecting rails: if a steel disc often takes the brunt of the blow, then a cast disc cuts rubber quite easily, while itself it also wrinkles, only less than a steel disc would wrinkle. However, the result is the same: in both cases, you will have to straighten the disk, and now look at the paragraph above.
What is the central (hub) hole of the disc?
This structurally empty hole is one of the most important points on disk. It is this hole that is put on the end of the axle when the wheel is attached to the car, and with this hole the disk should fit snugly against the axle hub - i.e. the diameter of the hub axle must be equal to the diameter of this hole. When buying alloy wheels, you need to make sure that central hole the same or at least more than the axis. Most alloy wheels are designed for either a specific car model or a number of such models, and for each of them they will have a central hole slightly larger than the hub, but the wheels will include special plastic gaskets in the form of rings, which you need to it will be easy to put on the hub, and when choosing alloy wheels, you just have to check if all 4 (5) rings are included in the kit.
How to choose alloy wheel bolts/nuts?
An equally fundamental issue in choosing new alloy wheels is bolts or nuts (depending on which design is on your car). You can find out that bolts or nuts do not fit for various problems, and here are the main ones:
- Nuts simply do not fit into the hole in the decorative hole on the disk and thus do not reach the studs.
- Bolt heads do not fit into these holes.
- The base of the cap (the plane of the nut/bolt that presses against the disc, pressing it) has a different angle of inclination than the disc. In this case, the planes of the nut/bolt and the disk are not parallel, as a result of which the disk is damaged during tightening.
- The bolts are too short for alloy wheels (because the walls of alloy wheels are thicker than steel ones).
It should be borne in mind that all these problems will lead to damage to the disc and, possibly, to the creation of an emergency on the road. But in general, very often rims come with bolts or nuts for their fastening.
Spokes (beams) of disks
The choice of the number and design of alloy wheels, of course, remains with the buyer. We will only note general rule: The more spokes, the safer such a disc will be.
What is rim width and offset (ET)?
One of the most important indicators of any disks are 3 most important characteristics: the diameter of the disk, its width and offset. The values of these indicators are marked with bulges next to each other on the disks themselves (moreover, both cast and steel). As a rule, on stamped discs they are applied on their outer side, and on cast discs, on the inner side on one of the rays or on a plane that is in contact with the brake disc or drum of the car.
- Diameter is the distance between the two most distant points of the disk in its longitudinal plane, not counting its rims. Diameter is measured in inches.
- The width of the disc is the distance between the two extreme points of the disc along the transverse plane, also not counting the rim, also measured in inches.
- Disc offset is the distance between the contact plane of the disc with the brake disc or drum of the machine and the central part of the disc in the transverse plane.
Don't choose alloy wheels the same size as the above three dimensions as your stock steel wheels - most often you won't find alloy wheels in the same size for your model. Look in the car's operating manual - sometimes the permissible values \u200b\u200bof these characteristics are written there, but rather look on the forum for your car model for a suitable dimension.
What is a PCD disc?
Disc PCD is the distance and number of disc mounting holes for bolts or nuts. The PCD value, respectively, is presented as two numbers, the first of which is the number of mounting holes, and the second is the diameter of the circle that these holes form between themselves (and around the hub hole), the circle of which is drawn through the centers of these mounting holes. For example, PCD 4 * 98 means that the disk has 4 holes for bolts or nuts, and the distance between the centers of two holes opposite from each other is 98 millimeters.
PCD equal to 100 for four- and five-bolt discs
Cosmetic treatment of alloy wheels
When choosing alloy wheels, important attention must be paid to their external coating and knowledge of how to care for certain coatings. So, just a painted cast wheel will last much longer than a chrome plated one.
Which manufacturer of alloy wheels to choose?
A very important factor is the manufacturer of the alloy wheels you are going to buy. The composition and technology of their production depends on this, which means how much the disks will be subject to corrosion and other chemical processes, how resistant to shock, and so on. A simple rule plays an important role here: the cheaper the discs, the lower their quality. Traditionally, high-quality discs are products of Kosei, OZ Racing, and the most budgetary discs are Russian production(Scud and others), K&K.
Properly and well-chosen wheels for a car are not only your safety and care for passengers, but also low fuel consumption along with an extended transmission life and a bewitching look of a stylish car.
Let's try to figure out how to choose the right alloy wheels and operate them correctly. The opinions of intelligent experts in this field and the recommendations of popular manufacturers of light alloy products will be taken into account.
Disk types
All rims can be divided into two groups - steel and light alloy (casting). The design of stamped wheels is simple and uncomplicated. vyshtampovyvayut and individual parts are interconnected by spot welding. Then the disk is painted and sent to the store or to the conveyor.
This way of equipping a car with disks is simple and inexpensive. A significant mass of cars coming off the assembly line have just such wheels. Casting installation is already additional option for which you need to pay a decent amount.
Before choosing alloy wheels instead of steel ones, in favor of the latter, we can say that they have more, which means that after strong impacts they do not crumble or crack, but only deform. This feature allows you to restore the disc, even if the edges are heavily crumpled.
A significant drawback of stamped products, which is critical for many motorists, is the mass. Moreover, it cannot be reduced, because insufficient wall thickness significantly reduces the strength indicators of the entire wheel. In addition, steel models are susceptible to corrosion if the integrity of the protective coating is compromised. This also includes a monotonous and boring appearance, difficulties with and a negative impact on the dynamics of acceleration.
Alloy wheels
Before choosing alloy wheels, it is useful to know some of the benefits. Alloy models have extensive design options along with high precision manufacturing. They are able to remove most of the heat from the main nodes, but the most important thing is the lightness of the design. It is possible to judge the specific merits of certain models if it is known how they are cast and with what alloy. So in this case the wheel is different from the wheel.
Ordinary models are made by casting or forging from stable alloys, where the basis is aluminum, titanium or magnesium. Magnesium and titanium models are much stronger and lighter than aluminum wheels. Before choosing magnesium-based alloy wheels, be aware that they are less resistant to corrosion, which means that you will have to constantly take care of the multi-layer protective coating. As for titanium, this is already an elite group, which is equipped with very expensive, sports and simply prestigious cars. For everyday driving on our roads, titanium models are simply a pity to use. Despite the strength of such products, they are prone to scratches.
Difficulties of choice
Before choosing alloy wheels for a car, remember that the purchase should be determined by your needs and, of course, the amount in your wallet. If your path is megacities and large cities, then ideal option will be magnesium or aluminum casting. Do you have free funds? Please, titanium models are beautiful, ultra-reliable and will be a great addition to the elite surroundings.
If you value reliability, often drive out of town on bad roads and do not attend secular parties in your car, then it is better to stop at steel, stamped or forged products. In this case, they will not only be more practical, but will also save you the lion's share of the family budget.
How to choose the right alloy wheels for your car
In order to correctly select one or another model of a disk specifically for your car, it is necessary to clearly clarify some critical parameters. First of all, we find out the width and diameter of the disk. Then we specify the location of the mounting holes and their number. Next, pay attention to the diameter of the hub of your car and the departure rate. All main mounting dimensions can be found in the catalogs of tire and wheel manufacturers or you can measure everything yourself using a special tool. Before choosing alloy wheels for a car, and if you suddenly have any doubts, it’s better to go to a smart tire shop and figure everything out there, drawing all the dimensions and parameters that interest us on a piece of paper.
Disc diameter
This parameter is selected according to the recommendations of the manufacturer of your car. It must exactly match the landing diameter of the wheel. Recently, there are more and more extreme people who seek to increase the mounting diameter. For example, a 15-inch fit is rolled under 16, 17, or even 18-inch wheels.
All this is done for the installation, which, on the one hand, increases driving performance for the better, and on the other hand, increases the load on the main suspension units. And the comfort of driving on such tires is not the best. Before choosing alloy wheels of one diameter or another, you must decide for yourself what is more important - sports performance Or driving comfort?
Rim width
If the manufacturer's recommendation for your rims for mounting diameter does not exceed 14 inches, then the width of the rim will fluctuate between 0.5-1.0 inches. For mounting diameters greater than 15 inches, the width will be slightly higher - 1.1-1.5" for the rim.
Which alloy wheel to choose is up to you, but a factory-width one is a better and more practical option. The operation of non-standard wheel models for your car is fraught with changes in the design profile of the tire, as a result of which the basic driving characteristics (steal resistance, reaction to wheel and lateral stiffness).
wheel offset
Reach is the distance between the mounting plane of the wheel and the longitudinal plane of the rim (symmetry). Wheel offset can only have three values: zero, positive, and negative. The indicator is indicated by a numeric or alphabetic value. For example, ET40 (mm) is a positive offset, and ET-40 is already negative, so do not get confused and take the minus sign for a dash or hyphen. The literal value is usually denoted by the words OFFSET and DEPORT.
Separately, it is worth noting that the larger the offset, the deeper the car sits in the wheel grooves. And the smaller this figure, the more the wheel sticks out of the niche. Most car owners tend to reduce this figure. In general, it is not entirely correct to deviate from the standard values \u200b\u200bthat were set on the factory conveyor, but sometimes, due to certain circumstances (frequent driving on bumpy or, conversely, perfectly flat roads), you can adjust the departure in the right direction for a more comfortable ride.
In recent decades, stamped steel wheel rims have been widely replaced by cast models. Some car enthusiasts do this to improve the appearance of their cars, but for most of them, not only the aesthetic effect is important, but also improved performance.
So, what are alloy wheels and what are their advantages over stamped ones?
What are alloy wheels?
As it is easy to understand from the name, alloy wheels are products made by casting. Steel is not suitable for them for a number of reasons, therefore, aluminum alloys are used mainly for discs, sometimes more exotic alloys based on magnesium.
The finished disk is a solid casting, which, in order to acquire greater strength, is subjected to a hardening procedure that relieves residual metal stresses. After these technological operations, the surface of the disk is polished and covered with a special varnish to maintain a stable gloss.
The shape of the disc is the result of the painstaking calculation of the leading engineers of the largest automotive companies. The composition of the alloy and the technology of its preparation from the most famous manufacturers is often almost impossible to copy. That is why, despite their external similarity, discs produced under world brands are much more reliable and durable than their cheap Chinese copies.
Advantages of alloy wheels
When deciding to replace stamped steel wheels with alloy cast ones, each car owner must understand why he is doing this and what he will get as a result of the replacement.
So, what are the advantages of alloy wheels compared to stamped ones?
1. Light weight. Aluminum alloy wheels, in addition, in the absence of hubcaps, weigh much less than stamped predecessors - sometimes the weight reduction reaches 50% of the previous one. As a result, the load is reduced, and the car becomes more manageable, stable and obedient on the road. In addition, ride comfort is increased, as the suspension absorbs shocks and impacts more effectively. An important factor is the reduction of suspension wear, as a result of which the cost of maintaining it in good technical condition is reduced.
2. Openness brake system. Due to the absence of caps, the inside of the wheel remains open during the movement and cools naturally. This improves the performance of the brake system, provides it with greater reliability and reliability.
3. Corrosion resistance. Unlike steel, which rusts easily, aluminum alloys are resistant to corrosion even when the outer lacquer is deeply scratched.
4. Superior design. Wheel hubs form an elegant pattern, individual for each model. Well-chosen wheels can significantly improve the appearance of the car, give it individuality and enhance the dignity of the body design.
Disadvantages of alloy wheels
As happens everywhere, the disadvantages inherent in solid-cast wheels are an extension of their advantages. So, the strength obtained by hardening turns into brittleness: with a strong impact, the cast disk does not bend, but bursts. It is impossible to continue driving in this case, and if there is no spare tire in the trunk, the only way out is to call a tow truck. A broken disk can no longer be repaired - it only needs to be replaced with a new one.
A variety of disk designs can also turn into problems: if you need to replace one disk, it can be difficult to find an identical one in size and pattern. True, today the task is facilitated by Internet commerce, thanks to which disks of the desired shape can be found and ordered even on the opposite side of the planet.
The exposed spokes and rims that adorn the car in such a way need constant washing and cleaning, as road dust and dirt constantly penetrate into the recesses. If cleaning is not taken care of, the accumulated dirt can cause wheel imbalances, resulting in uneven wear And premature exit failure of the suspension elements.