What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Use performance self-tapping screws for self-tapping screws with a diameter of 0.8mm to 12mm. For this type of screw, it generally has a high hardness. Self-tapping screws must be screwed into the test, that is, screw the screw into a test plate to check whether the hardness of the screw meets the standard. The shape of the drill tail, the hardness of this kind of screw is very strong. Compared with ordinary screws, it not only has better maintenance ability, but also has a very strong effect in connecting objects. For screws with this performance, it is generally not necessary. Auxiliary processing can directly drill a hole on the object and lock it into the object, which is not only very convenient to use, but also greatly improves work efficiency. This kind of drill screw can be said to be the first choice of the staff in various fields.
The existing nut fasteners are generally used to fix the bolts to fix the devices with holes. However, during the operation of most devices, the bolts and nuts are easily loosened and separated due to mechanical vibration, causing long-term vibration. It will cause the nut to separate from the bolt, affecting the safety and stability of the device during operation. At the same time, in the connection between the bolt and the nut for a long time, the external dust easily enters the connection, resulting in the accumulation of dust, making the bolt and nut difficult to disassemble. Affect the use of fasteners.
The semicircular key is a kind of key, the upper surface is a plane, the lower surface is a semicircular arc surface, the two sides are parallel, commonly known as the crescent key. It is basically the same as the flat key connection method, but it is more convenient to manufacture and disassemble than the flat key, and is especially suitable for the connection between the tapered shaft and the hub. The half-round key transmits torque on the side, but the keyway is deep, which weakens the shaft greatly. Due to the deep keyway, the bottom of the keyway is easily deformed after the shaft is heat treated. Therefore, when the semicircular key and the keyway are assembled in a transitional fit relationship, the interference between the lower part of the semicircular key and the bottom of the keyway often occurs, resulting in difficult or impossible assembly. Assembly situation. In order to solve the above technical problems, the current method is to make the thickness of the semicircular key appropriately thin, so that the semicircular key and the keyway are clearance fit, which brings about a large gap between the upper part of the semicircular key and the keyway, and the semicircular key is in operation. Difficult to locate in the keyway, affecting smooth transmission.
In general, the electroplating of combination screws generally refers to the de-plating of iron combination screws. Electroplating is divided into environmental protection and non-environmental protection. Commonly used combination screw electroplating colors include green color zinc, green blue zinc, green white zinc, green nickel, red color, white zinc, white nickel, etc. Cross recessed combination screws, hexagonal combination bolts and self-tapping combination screws are used in the same way as the corresponding cross recessed screws, hexagon head bolts and self-tapping screws. The main feature of these combination screws is that they are equipped with corresponding washers, which are very convenient to use.
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