1、Check if the trademark identification is complete. The packaging quality of authentic products is good, with clear handwriting on the packaging box and vivid overprinting colors. When making a purchase, it is important to carefully identify and avoid buying counterfeit or inferior products.
2、 Check for any deformation in the geometric dimensions. Some parts are prone to deformation due to improper manufacturing, transportation, and storage. The outer edge of the skeleton free oil seal should be straight, and it should be deformed by hand. After releasing it, it should be able to return to its original state. When selecting various types of pads, attention should also be paid to checking the geometric dimensions and shape.
3、Check if the joint is flat. During the handling and storage of spare parts, burrs, indentations, damages or cracks often occur at the joint due to vibration and collision, which affects the use of the parts.
4、Check for rust on the surface of the parts. The more important the spare parts, the higher the precision, and the stricter the packaging for rust and corrosion prevention. Qualified spare parts surfaces have both a certain degree of precision and a shiny finish.
5、Check if the protective surface is intact. Most parts are coated with a protective layer at the factory. Protect piston pins and bearing shells with paraffin wax; Apply anti rust oil to the surface of piston rings and cylinder liners and wrap them with packaging paper; Immerse valves, pistons, etc. in rust proof oil and seal them in plastic bags.
6、Check if the bonded parts are loose. The parts are pressed together, and the friction plates are riveted or glued to the steel plates; The skeleton of the paper filter element and the filter paper are glued together; The wire ends of electrical equipment are welded together. choose
7、Check if the rotating components are flexible. When selecting rolling bearings, support the inner ring of the bearing with one hand and rotate the outer ring with the other hand. The outer ring should be able to rotate quickly and freely, and then gradually stop rotating. If the rotating parts do not rotate properly, it indicates internal corrosion or deformation, and should not be purchased.
8、Check if there are any missing parts in the assembly components. Legitimate assembly components must be complete and in good condition.