Standards are norms, and each country and sector has its own standards. The most commonly used standards in our daily business are as follows: GB—China National Standard (National Standard) ANSI—American National Standard (American Standard) DIN—German National Standard (German Standard) ASME—American Society of Mechanical Engineers Standard JIS - Japanese National Standard (Japanese Standard) BSW - British National Standard GB - National Standard is one of many standards in my country, as well as industry standards, professional standards and department standards. National standards are divided into: GB (mandatory standards) and GB/T (recommended standards) and GBn (national internal standards) and so on. We usually see GB30, GB5783, etc. are mandatory standards. In addition to some basic dimensions such as head-to-side, head thickness, etc., the above standards are mainly different in the threaded part. The threads of GB, DIN, JIS, etc. are all in MM (millimeters), which are collectively referred to as metric threads. Another thread like ANSI, ASME, etc. is called American standard thread in inches. In addition to metric threads and American threads, there is also a BSW-imperial standard, whose threads are also in inches, commonly known as Wyeth threads.
The force condition of the screw is broadcasted: 1) Self-weight G; 2) Torque M required to overcome material resistance; 3) Axial force P generated by material pressure. Screw screw screw is generally scrapped due to long-term wear, the gap between the screw and the barrel is too large and cannot be extruded normally, but there are also examples of damage due to improper design or improper operation. Therefore, the screw should also meet certain strength requirements. 4) The dangerous section of the screw is generally at the smallest thread root diameter in the feeding section. According to material mechanics, for plastic materials, the composite stress is calculated by the third strength theory, and its strength conditions are:
Hex cap screw and Hex bolt Hex bolt As the name suggests, it is a male threaded fastener with a hexagonal head, designed to be turned with a wrench. According to the ASME B18.2.1 standard, the head height and shank length tolerance of the hexagon head screw (Hex cap screw) is smaller than that of the general large hexagon bolt (Hex bolt), so ASME B18.2.1 hexagon screw is suitable for installation in all hexagon bolts that can be used. places, also including places where the large hex bolts are too large to be used. The screw head of the hexagon socket screw is round on the outside, and the middle is a concave hexagon, and the hexagon screw is the kind of common hexagonal screw head. The hexagon socket head screwdriver looks like a '7'. Cut two sections of a hexagonal steel bar and bend it at 90 degrees to form a hexagon socket head screw wrench, which is sold in hardware tool stores. Hexagon socket screwdrivers are not so-called mobile phone special screwdrivers. Mobile phone special screwdrivers can be bought at the booths that sell repair tools in the electronics market. Hexagon socket head cap screws are often used in machinery, mainly because they are easy to fasten, disassemble, and not easy to slip. The Allen wrench is generally a 90° bend. One end of the bend is long and one side is short. When using the short side to drive screws, holding the long side can save a lot of force and tighten the screws better. The long end has a round head (a hexagonal cylinder is similar to a sphere) and a flat head. The round head can be easily slanted and disassembled, and some parts that are inconvenient to lower the wrench can be installed. The manufacturing cost of the outer hexagon is much lower than that of the inner hexagon. Its advantages are that the screw head (the force position of the wrench) is thinner than the inner hexagon, and some places cannot be replaced by the inner hexagon. In addition, machines with low cost, low power strength and low precision requirements use much less hexagon socket screws than external hexagon screws. [1] Socket cap screw, also known as socket head screw or Allen bolt, is a screw with a hexagonal inner hole on the head, with a hexagonal ruler (hex key, Allen wrench or Allen key) Tighten or loosen only after inserting into the inner hole. The most commonly used hexagon socket head screws are cylindrical head screws with a head diameter of about 1.5 times the main diameter of the thread (1960 series). Countersunk head cap screw. The countersunk hole design allows the screw head to be rotated without being exposed on the surface of the fixed object, so it is mostly used in places where the surface is small and it is inconvenient for traditional wrenches to use.
Slotted Round Head Wood Screws GB 99-86 Slotted Countersunk Head Wood Screws GB 100-86 Slotted Half Countersunk Head Wood Screws GB 101-86 Hexagon Head Wood Screws GB 102-86 Cross Recessed Round Head Wood Screws GB 950-86 Cross Slotted countersunk head wood screws GB 951-86 Cross recessed countersunk head wood screws GB 952-86
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
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: wholesale DIN7991 screws, plastic plastic washers, flat head rivets, hexagonal full-tooth screws and other products, we can provide you with suitable fastening for you piece solution.