Maintenance requirements for Heavy Hex Bolt :
1. The bolts should be able to penetrate freely into the bolt holes. The reaming of the bolt holes cannot be carried out by oxygen cutting, and the amount of reaming should be carried out according to the design of the construction project. The diameter of the hole after reaming needs to be less than 1.2D.
2. When each operation reaches 12000km, it is necessary to carry out secondary maintenance on the bolts. The bolts should be equipped with the engine oil pan, and then check the condition of the piston pins of the car engine. If the distance between the piston pins of the car engine is too large, they should be removed and replaced, and the connecting rod bolts should also be replaced at the same time. If it is found that abnormal noise and unstable operation of the automobile engine are found in the daily operation history, the inspection must also be carried out immediately.
3. Every time the repair is carried out, the new connecting rod bolts need to be checked again. It is also necessary to check the guiding parts of the bolts, the top of the external thread head, whether there are pits or cracks in this part, and whether the tooth pitch and the tooth profile of the external thread are normal. If there is any abnormality in the above parts, it cannot be used continuously.
4. When installing the connecting rod bolt cover, it must be carried out with a torque wrench. When tightening, it must be according to the specified specifications and models to avoid excessive or excessive torque.
5. The crankshaft bolts should be manufactured by the supporting facility factory.
6. After the bolt is a spherical joint, the spherical joint must be firmly connected with the bolt, and the bolt must be screwed into the bolt ball, so the external thread size should exceed 1.0d, and the area of the joint is not loose or void.
7. The friction surface that the bolts must be connected to should be clean, tidy, dry, and free of welding slag, burrs, welding spatter, compound scale, sparkle, waste, etc. Unless there are special circumstances, it should not be painted.