Axle is one of the key components of semi-trailer, which undertakes the functions of vehicle load-bearing, braking and driving maintenance. Many car owners will face a problem when purchasing axles: why do the prices of axles that look similar differ so much? Today, let's talk about this topic.

1、 Selection of raw materials.

In fact, no matter what brand of axle, its raw materials are basically steel. However, there are still great differences between steels. For example, the prices of steels with different strength, hardness, self weight and toughness are naturally different.

According to the current market price, the average price of high-strength alloy seamless steel pipe is about 1500-2000 yuan / T compared with ordinary steel pipe.

The stronger the comprehensive mechanical properties of steel, the higher the indicators of load-bearing, durability and safety of the axle made of steel, and the price of the finished axle will naturally be higher.

On the contrary, those low-quality steels can save the axle factory a lot of raw material costs, but the performance is difficult to meet the standard, and even there are cracks invisible to the naked eye. I'm afraid even the manufacturer can't guarantee the performance of the axle made by this.

2、 Production process.

At present, the domestic axle brands can be roughly divided into two types: one is to have its own special factory, and the axle is in its own hands from the selection of raw materials to the final assembly and molding; The other is to buy axle semi-finished products and accessories from others and only assemble them by yourself, or recycle the old axle for renovation and sale.

Generally speaking, the former has a large production scale and strong technology, experience and capital strength; The latter has a smaller production scale, mainly small brands, and even some "three noes" products.

As a result, the price of trailer bridges in the market is basically divided into two camps. For those whose prices are too cheap, car owners should take a good look at the relevant qualifications.

So, are there any differences in the production processes of those large axle enterprises? To be honest, after years of development, the domestic axle industry has basically popularized relevant technologies and processes in these large enterprises. Its production lines and other instruments or equipment are almost common in the industry, and there is little difference in technology.

However, this does not mean that the production of axle is simple. Let's take Darong axle, an axle enterprise in Liangshan commercial vehicle production base, as an example to briefly introduce the production steps of axle.

1. Selection of raw materials: 20Mn2 high-strength alloy seamless steel pipe is used for Darong axle, and the wall thickness varies from 9mm to 22mm according to the type of axle;

2. Cut the steel pipe according to the drawing and cut the raw material according to the drawing;

3. Hot rotary rolling: the maximum temperature can reach 1300 ℃, mainly through heating to improve the processing performance of steel and reduce casting defects;

4. Preliminary treatment of shaft head: cut the shaft head according to the drawing to ensure the machining size of shaft head;

5. Cold pushing side: if the customer needs square tube, the round tube needs to be processed into square tube by cold pushing side technology;

6. Full automatic quenching: digital medium frequency induction quenching machine, temperature 865 ℃, through heating to promote the transformation of austenite to martensite in steel, and improve the hardness and strength of steel;

7. Heat preservation and tempering: the temperature is generally about 480 ℃, which is used to eliminate the thermal stress of steel after quenching, stabilize the transformed martensite and improve the toughness of steel;

8. Shot blasting and sand blasting: clean the residual oxide scale and oil stain after heat treatment process;

9. Axle straightening: automatic multi-point straightening equipment, with an accuracy of 0.4-0.5mm;

10. Spraying primer: provide isolation, moisture-proof, oxidation and corrosion prevention for the axle, and improve the adhesion of the subsequent finish paint;

11. NC machine tool processing: boring, milling, drilling and precision grinding of the shaft body to ensure the accuracy of the shaft head;

12. Medium frequency induction treatment: mainly strengthen the shaft head to prolong the service life of the axle;

13. Shaft head accuracy inspection: deal with the oxide scale at the shaft head after processing, accept the size and thickness of the shaft head, and apply anti rust oil after passing the inspection;

14. Topcoat spraying: cooperate with the primer to protect the shaft from erosion;

15. Welding semi-finished products: install shaft head nuts and locking gaskets, and weld brake base plate, spherical bearing and air chamber seat;

16. Anti fatigue test: axle semi-finished products are randomly inspected. After millions of anti fatigue tests, the subsequent steps are entered after passing the test;

17. Finished product assembly: on the basis of welding semi-finished products, install wheel hub, brake drum / brake disc, inner and outer bearings and other components. Darong axle accessories partners are well-known domestic manufacturers, ranking among the best in their respective fields, and the quality of accessories is stable and reliable;

18. Finished product quality inspection: online and offline quality inspection methods are adopted to detect the quality of finished axle.

19. Warehousing: after passing the quality inspection, Darong axle enters the warehouse and arranges delivery according to customer needs.

Therefore, the production steps of a qualified axle are very cumbersome, and the human and material costs involved during the period are also relatively high, so the price of its finished products will naturally rise. But correspondingly, such an axle is also reassuring in terms of service performance.

3、 Brand premium.

This point is to undertake the previous content. Why does the price of axles of the same specification still vary a lot under the condition of great difference in production technology? That is because different manufacturers have different market positioning for their products and different operating costs.

Some brands follow the high-end route. After being linked to the "high-end", the price will not be cheap. Then they will spend a lot of money on advertising and publicity. These costs will eventually be paid by customers. Just like the bags produced with the same materials and processes, the price is different with different labels, although their performance is the same. The same is true when it is placed on the axle.

It should be noted that brand premium is not synonymous with quality and performance. Those axles that take the cheap route, such as the Darong axle mentioned above, are not poor in quality and performance, but the price is more acceptable to customers. The price performance ratio is still very high, which is very suitable for car owners with a low budget.

In addition, many car owners want to spend a small amount of money to grab a lot of money to buy quality and performance. This psychology is understandable, but it is not realistic. After all, the production cost is there. It is suggested that car owners also need rational consumption and don't blindly pursue cheapness, otherwise they may be deceived by bad manufacturers. The price is cheap in the early stage, but they may face a series of use problems in the follow-up. If they spend money to repair it, it will be disturbing and expensive. It's better to buy a cost-effective product directly.