How to choose accessories for cars？

What is a good way to buy auto parts products? How to buy the most suitable and cost-effective auto parts? Here, I recommend the following tips to help you choose the best auto parts: 1. See if the trademark logo is complete The outer packaging of authentic auto parts is of good quality. The handwriting on the box is clear. The overprint color is bright. The box. On the bag. Should be marked with the product name, specification model, quantity, registered trademark, factory name, factory address and telephone number, etc. Some The manufacturer also puts its own mark on the accessories. Some important components such as generators, distributors, fuel injection pumps, etc. are also equipped with instruction manuals, certificates of conformity and inspector seals to guide users in the correct use and maintenance. Careful recognition when purchasing Clear. In case you bought fake and shoddy products. 2. See if the geometric dimensions are deformed Some auto parts are easily deformed due to manufacturing, transportation, improper storage, and inspection. During inspection, the shaft parts can be rolled around the glass plate. Check whether there is light leakage at the joint between the part and the glass plate to determine whether it is bent. Choose a clutch from When the steel plate or friction plate of the moving disc. The steel plate. The friction plate can be held in front of your eyes to observe whether it is warped. When purchasing an oil seal, the end face of the oil seal with a skeleton should be in a perfect circle. It can be attached to the flat glass without bending , The outer edge of the non-framed oil seal should be straight. Hold it by hand to deform it. It should be able to return to its original shape after letting go. When purchasing various types of gaskets, attention should also be paid to checking the geometric size and shape. 3. See if the joint is flat During the transportation and storage of automobile parts, due to vibration, bumps, burrs, indentations, breakages or cracks are often generated in the joints, which affect the use of parts. Pay attention to inspection when purchasing. 4. Check for rust on the surface of the part The surface of qualified parts. It has both a certain precision and a bright finish. The more important the parts. The higher the precision. The stricter the rust and corrosion protection of packaging. Pay attention to inspection when purchasing. If you find that the parts have rust spots. Mold spots or cracks in the rubber parts. Loss of elasticity. Or there are obvious cutting tool lines on the surface of the journal. It should be replaced. 5. See if the protective surface is intact Most parts are coated with a protective layer before leaving the factory. For example, piston pins, bearing bushes are protected with paraffin, piston rings, cylinder liners are coated with anti-rust oil and wrapped with wrapping paper, valves, pistons, etc. are dipped in anti-rust oil and then packaged in plastic bags. If it is found that the sealing sleeve is damaged during the purchase, the packing paper is lost, the anti-rust oil or paraffin wax is lost, it should be returned. 6. See if the glued parts are loose An accessory composed of two or more parts. The parts are press-fitted, glued or welded. There is no looseness between them. For example, the oil pump plunger and the adjusting arm are combined by press-fitting, The clutch follower and the steel plate are riveted. The friction plate and the steel plate are riveted or glued. The paper filter element skeleton and the filter paper are glued together, and the thread ends of the electrical equipment are welded. If any looseness is found during purchase, it should be replaced. 7. See if the rotating parts are flexible When purchasing a rotating part assembly such as an oil pump. Rotate the pump shaft by hand. You should feel flexible and free from jamming. When purchasing a rolling bearing. Support the inner ring of the bearing with one hand. Turn the outer ring with the other. The outer ring should be able to rotate quickly and freely. Then Gradually stop. If the rotating parts do not rotate properly, it means that the internal rust or deformation. Do not buy. 8. See if there are any missing parts in the assembly The regular assembly parts must be complete and intact to ensure smooth assembly and normal operation. If the individual small parts on some assembly parts are missing, it will make the assembly parts unable to work or even scrap. 9. See if the assembly marks are clear. In order to ensure that the assembly relationship of the mating parts meets the technical requirements, some parts (such as timing gears) are engraved with assembly marks on the surface. If there is no mark or the mark is blurred and unrecognizable, it will bring great difficulties to assembly. Even assembly errors. 10. See if the mating surface is worn If there are signs of wear on the mating surface of the parts, or the painted parts find old paint after removing the surface paint, it is mostly disguised as waste parts. At this time, you can request a return. 11. See if the surface hardness meets the standard The surface hardness of each mating part has specified requirements. After confirming the purchase and negotiating with the merchant, the stubble of the hacksaw blade can be used to test the scratch. It is slippery during scratching without scratches. It means that the hardness is high, and there are slightly shallow marks after scratching. The hardness is high, and there are obvious marks after scratching. It means that the hardness is low (be careful not to damage the working surface when trying to scratch).