What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Standard screw is one of the fasteners commonly used for fastening and assembly. Standard screws and flat washers, grade A, and standard spring washers, are used in combination, and are widely used in the assembly of various products. For manufacturers who use combination screws in small and medium batches, the process of combining screws, spring washers and flat washers generally adopts the method of assembling screws by workers' bare hands. This method is tedious and repetitive, wastes human resources, is time-consuming and labor-intensive, and it is difficult to ensure the normal operation of the workshop. assembly progress. The screw assembly machines currently on the market can replace manual assembly screws, but this type of equipment has disadvantages such as bulky size, high cost, complex structure, inconvenient non-standard manufacturing and maintenance, high noise, and power consumption.
The gasket refers to the part between the connected part and the nut, which is generally a flat metal ring, which is used to protect the surface of the connected part from scratches by the nut and disperse the pressure of the nut on the connected part.
The nut specification table is to unify all kinds of nuts in detail, and use the table to subdivide some specifications of the nuts. There are many types of nuts, and there are nuts of different materials. Each type of nut has different specifications, and each type of screw also has its mechanical properties and functions. · Square nut grade C GB 39-88 · Hexagonal nut grade C GB /T41-2000 · Hexagonal thick nut GB 56-88 · Wing nut GB 62-88 · Ring nut GB 63-88 · Combined cap nut GB 802 -88 · Spherical Hex Nut GB 804-88 · Fastening Nut GB 805-88 Knurled High Nut GB 806-88 · Knurled Thin Nut GB 807-88 · Small Hexagonal Extra Flat Fine Thread Nut GB 808-88 · Embedded Round nut GB 809-88 · Small round nut GB 810-88 · Round nut GB 812-88 End hole round nut GB 815-88 · Side hole round nut GB 816-88 · Slotted round nut GB 817-88 · Type 1 non-metallic insert hexagonal lock nut GB /T 889.1-2000 · Type 1 non-metallic insert hexagonal lock nut with fine thread GB /T 889.2-2000 · Cap nut GB 923-88 · Type 1 hexagonal nut GB / T 6170-2000 · Type 1 Hexagonal Nuts with Fine Thread GB /T 6171-2000 · Hexagonal Thin Nuts GB /T 6172.1-2000 · Non-metallic Insert Hexagonal Locking Thin Nuts GB /T 6072.2-2000 · Hexagonal Thin Nuts with Fine Pitch GB /T 6173-2000 · Hexagonal thin nuts without chamfer GB /T 6174-2000 · Type 2 hexagon nuts GB /T 6175-2000 · Type 2 hexagon nuts with fine pitch GB /T 6176-2000 · Hexagon flange nuts GB / T 6177.1-2000 · Hexagon flange face nuts with fine pitch GB /T 6177.2-2000 · Type 1 hexagon slotted nut - Grade A and B GB 6178-86 · Type 1 hexagon slotted nut - Grade C GB 6179-86 · 2 Type Hexagonal Slotted Nuts-A and B Grades GB 6180-86 Hexagonal Slotted Thin Nuts-A and B Grades GB 6181-86 Type 2 Non-metallic Insert Hexagonal Lock Nuts GB/T 6182-2000 Non-metallic Inserts Hexagon flange face lock nuts for non-metal inserts GB /T 6183.1-2000 · Non-metallic insert hexagonal flange face lock nuts with fine thread GB /T 6183.2-2000 · Type 1 all-metal hexagonal lock nuts GB /T 6184-2000 · Type 2 all-metal hexagonal lock nut GB /T 6185.1-2000 · Type 2 all-metal hexagonal lock nut fine pitch GB /T 6185.2-2000 · Type 2 all-metal hexagonal lock nut Grade 9 GB /T 6186-2000 · Full Metal Hexagon Flange Face Lock Nuts GB /T 6187.1-2000 · All Metal Six Angle flange face locking nut fine pitch GB /T 6187.2-2000 · Type 1 hexagon slotted nut with fine pitch A and B grades GB 9457-88 · Type 2 hexagonal slotted nut with fine pitch A and B grade GB 9458-88 · Hexagonal Slotted Thin Nut Fine Thread Grade A and B GB 9459-88 · Welded Square Nut GB /T 13680-92 · Welded Hexagonal Nut GB /T 13681-92 · Flat Head Rivet Nut GB /T 17880.1-1999 · Countersunk Head Rivet Nut GB /T 17880.2-1999 · Small countersunk head rivet nuts GB /T 17880.3-1999 · 120° small countersunk head rivet nuts GB /T 17880.4-1999 · Flat head hexagonal rivet nuts GB /T 17880.5-1999 · Hexagonal nuts for precision machinery GB /T 18195-2000
Type 1) Slotted ordinary screws are mostly used for the connection of smaller parts. It has pan head screws, cylinder head screws, countersunk head screws and countersunk head screws. The head strength of pan head screws and cylinder head screws is high, and they are connected to common parts; the head of semi-countersunk head screws is arc-shaped, and its top is slightly exposed after installation, and it is beautiful and smooth. It is generally used for instruments or Precision machinery; countersunk head screws are used where the nail head is not allowed to be exposed. 2) The head of the hexagon socket head cap screw and the hexagon socket head flower screw can be embedded in the component, which can apply a large torque and have a high connection strength, which can replace the hexagonal bolt. It is often used in joints where compact structure and smooth appearance are required. 3) Cross recessed ordinary screws have similar functions to slotted ordinary screws, and can be replaced by each other, but the cross recessed ordinary screws have higher groove strength, are not easy to be bald, and have a more beautiful appearance. When using it, it must be loaded and unloaded with the matching cross-shaped screwdriver. 4) Lifting ring screw Lifting ring screw is a kind of hardware accessories for load-bearing during installation and transportation. When in use, the screw must be screwed in to the position where the supporting surface is tightly fitted, and tools are not allowed to be tightened, nor is a load perpendicular to the plane of the lifting ring allowed to act on it. 5) Set screws Set screws are used to fix the relative position of the parts. Screw the set screw into the screw hole of the part to be fastened, and press its end against the surface of the other part, that is, to fix the former part on the latter part. Set screws are usually made of steel or stainless steel, and their end shapes are conical, concave, flat, cylindrical and stepped. The end of the tapered or concave end set screw directly presses the parts, and is generally used in places that are not often disassembled after installation; the end of the flat end set screw is smooth and does not damage the surface of the parts after tightening, and is used for frequent adjustment of the position. At the connection, only a small load can be transmitted; the cylindrical end fixing screw is used in the fixed position that needs to be adjusted frequently, it can withstand a large load, but the anti-loosening performance is poor, and anti-loosening measures should be taken when fixing; Set screws are suitable for fixing parts with thicker walls. 6) Self-tapping screws When self-tapping screws are used on the connected parts, threads may not be pre-made at the connected parts. Use the screw to tap the thread directly when connecting. It is often used to join thin metal plates. There are two types of taper end tapping screws and flat end tapping screws. 7) Self-tapping locking screw Self-tapping locking screw not only has self-tapping effect, but also has low screw-in torque and high locking performance. Its thread is a triangular section, and the surface of the screw is hardened and has high hardness. Its thread specifications are M2 ~ M12.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
