What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Due to the high demand for electronic products and the reduction of assembly line workers, in order to cope with the problem of labor shortage, manufacturing factories need to use automatic screw locking equipment to replace manual labor. In the existing automatic locking and paying equipment, most of them use a screw arranging machine to arrange the screws, and an electric screwdriver (electric batch) takes the screws back and forth, or the special equipment blows the screws into the electric batch to send the screws to the electric batch, and back and forth. The method of taking is too time-consuming, and the method of blowing air is not suitable for screws with small aspect ratios.
According to the properties of nuts, there are mainly national standard (GB), German standard (DIN), international standard (ISO), Japanese standard (JIS), American standard (ASTM/ANSI) and other standards. Among them, the national standard, German standard, and Japanese standard are represented by M (such as M8, M16), and the American system and the British system are represented by fractions or # (such as 8#, 10#, 1/4, 3/8). Commonly used national standard GB41 Ⅰ type hexagonal nut - C grade GB6170 Ⅰ type hexagonal nut - A, B grade GB6171 I type hexagonal nut - fine thread - A, B grade GB6172 hexagonal thin nut - A, B grade - chamfering GB6173 Hexagonal Thin Nut - Fine Thread - A, B Grade GB6174 Hexagon Thin Nut - B Grade - No Chamfer GB6175 II Hexagonal Nut - A, B Grade GB6176 II Type Hexagonal Nut - Fine Thread - A, B Grade GB6177 Hexagon Method Blue face nut - grade A GB55 hexagonal thick nut GB56 hexagonal super thick nut GB1229 large hexagonal nut (high strength for steel structure)
With the advancement of technology in various industries, the current structural design of screws has evolved from just simple locking to focusing on work efficiency during the locking process and not destroying the integrity of the objects to be locked. The new cases such as No. 556784 screw improvement and No. 289405 screw that integrates locking, stability, labor-saving, fast and multi-function which were previously designed and approved and published in the Central Taiwan Bulletin are the main representatives of screws. It is clear that It is learned that the two cases not only fully improve the shortcomings of the traditional simple locking screws, but also achieve the purpose of substantial improvement of the screws designed in each case in actual use.
High-strength hexagon head bolt combination screws for steel structures, mainly used in railway and highway bridges, boiler steel structures, industrial plants, high-rise civil buildings, tower and mast structures, hoisting machinery and their steel structures need to use friction-type high-strength bolt combinations for screws. It is characterized by an extra dodecagon at the end of the bolt, also known as the bolt. When installing, a special electric wrench must be used, which has two socket heads up and down, one is set on the hexagonal body of the nut, and the other is set on the decagon body of the outer hexagon screw. When tightening, apply a clockwise force to the nut, and apply an equal counterclockwise force to the dodecagon body of the bolt, so that the connecting neck between the end of the outer hexagon screw and the dodecagon body is subjected to torsion shearing until the neck is sheared. So far, the installation has come to an end. This torsion shear type high-strength outer hexagon screw is a one-time-use screw and generally cannot be removed after installation.
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