What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The pretreatment process is a key process that determines the quality of nickel-phosphorus plating on high-strength bolts. The purpose of this process is to remove the passivation layer on the surface of the bolt and prevent the regeneration of the passivation film. The execution of this process directly determines the degree of bonding between the substrate and the coating. Most of the quality accidents in production are caused by poor pretreatment of bolts. Before plating, the oil, rust and oxide scale attached to the surface of the bolt must be carefully removed; the difference with electroplating is that it should be inspected more carefully, and plating is absolutely not allowed on unclean bolts. ① Inspection of bolts: Visual inspection of the surface quality of bolts requires that any burrs left by processing must be removed, and sharp edges and corners must be rounded. ② Manual degreasing; ensure that the surface of the substrate is free of oil stains. ③ Soak and remove oil; boil the bolts in alkaline water to remove the surface oil. ④ Pickling: In order to prevent the alkaline degreasing solution from contaminating the flash nickel plating tank, electro-activation treatment is carried out with pickling solution before flash nickel plating. ⑤ Electro-activation; electro-activation treatment with acid solution. ⑥ Flash nickel plating; flash nickel plating should be used for low alloy steel to increase the bonding strength between the coating and the substrate.
A kind of nut provided by Yueluo. The nut is in the shape of a casing and is provided with a threaded section. The hole walls at both ends of the threaded section are respectively provided with an annular shape and two grooves, and the notch of the groove points to the hole core. The hole diameter at the notch of the annular groove at the front end of the screw-in direction is larger than the nominal size of the thread segment, and the hole diameter at the notch of the annular groove at the rear end of the screw-in direction is smaller than the nominal size of the thread segment.
Applications Automotive industry -- cars, trucks, buses, compressors, construction machinery, wind power equipment, fasteners, fasteners, agricultural machinery, foundry industry, drilling equipment, shipbuilding industry, military mining equipment, oil drilling rigs (onshore or offshore), public utilities, rail transit drives System metallurgical equipment rock hammer
In the current production process, the inner wall of the circlip is quantitatively and evenly lubricated, and then the rotating shaft is inserted into the circlip, so that the rotating axis can rotate in the circlip, thereby realizing the rotation function of the sun visor. However, since the circlip is tightly fitted with the rotating shaft, during the insertion process of the rotating shaft, the front end of the circlip can easily push the grease from the opening at one end of the circlip to the opening on the other end of the circlip, so that the rotating axis and the inner wall of the circlip are easily connected. There is little or no grease left between them, which can easily lead to a lack of lubrication between the shaft and the circlip, and dry friction between the shaft and the circlip, resulting in a series of problems such as abnormal noise, difficult operation, and poor durability.
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