Common classification and characteristics of fasteners Fasteners are general-purpose elements for fixing mechanical components and are widely used in various fields, such as aviation, automobiles, military industry, construction, etc. According to different uses and needs, fasteners can be divided into different types. Below, maijin will introduce some common classifications and their characteristics.
Screws Screws are commonly used fasteners and are mainly used to connect mechanical components. According to different uses and needs, screws can be divided into different types, such as threaded steel nails, machine screws, wood screws and so on. Screws are often made of steel, but there are also some special requirements that require the use of different materials, such as stainless steel, copper, and so on. There are two main types of screws: metric screws and inch screws. Metric screws are widely used due to their versatility. There are a variety of thread angles to choose from, including 60 degrees, pointer angle (55 degrees), spring tide angle (30 degrees), etc. Threads with different angles have different uses and can be selected according to specific needs.
2. Nuts Nuts are a common fastener and are usually paired with screws. Together they hold the component together, making it more stable and stronger under forces. According to different uses and needs, nuts can also be divided into different types, such as hexagonal nuts, solid nuts, flange nuts and so on. Hexagon nuts are one of the common nuts, usually paired with hexagon screws, suitable for various applications. Their size and thickness can be adjusted as needed. Practical nuts are often used in high temperature or high pressure applications as they are able to withstand higher temperatures and pressures. Flange nuts are commonly used in many complex mechanical devices to secure two or more components together more firmly.
3. Bolts Bolts are usually made of steel, and they are used together with nuts to form a common fixing element. The main characteristic of a bolt is its head design, usually hexagonal, square, capped, etc. The length and width of the bolts can also be fine-tuned as needed to ensure that the various components are better fixed to each other.
4. Pin The lock pin is an axial locking device connected by a cone-shaped tenon and a cone-shaped hole. Its shaft portion is usually made of stainless steel or copper, although other materials may also be used. They are commonly used in hinges, ball joints, handles, etc. to provide more stability and rigidity to these connections.
5. Stud A stud is a threaded connection device, usually used to connect two components. Its main features are long, thin thread, no head, and will not loosen due to vibration and shock. They are usually used to provide stronger fixation for mechanical components under harsh working conditions, such as high temperature, high voltage, high current, etc. The above are the classification and characteristics of some common fasteners. By understanding their different characteristics, we can ensure the stability and safety of mechanical equipment when selecting appropriate fasteners, and provide more guarantees for safe production.
How many types of parts does the fastener contain? Fasteners are a general term for a type of mechanical parts that need to be used when two or more parts are tightened and connected into a whole, and they are also called standard parts in the market. Fasteners generally include anchor bolts, studs, screws, nuts, self-tapping screws, wood screws, sealing rings, flat washers, pins, bolts, components and connecting pairs, welding studs and other parts.
Today I will briefly explain some of the parts.
(1) Anchor bolt: a type of fastener composed of the head and the extruder screw, which must cooperate with the nut to tighten and connect two parts with buried holes. The connection is detachable .
(2) Stud: A type of fastener with no head and only two sides with external threads. When connecting, screw one end of it into the part with the internal thread hole, and pass the other end over the part with the buried hole, and tighten the nut so that the two parts are tightened and connected into a whole. This kind of connection is called stud connection, and it is also a detachable connection. One of the parts mainly used for connection is relatively large in thickness, compact in structure or unsuitable for bolt connection due to frequent disassembly and assembly.
(3) Nut: Contains internal thread holes, generally flat hexagonal columns, or flat columns or flat cylinders, matched with anchor bolts, screws or steel frame screws, used to tighten and connect two parts, make it a whole.
(4) Screw: A type of fastener composed of the head and the extruder screw. According to the field of application, it can be divided into three categories: steel frame screws, set screws and special purpose screws. The installation screw is mainly used for the fast connection between a part with a set screw threaded hole and a part with a buried hole, without nuts. Set screws are mainly used to fix the relative position between two parts, and the special purpose screws are used as lifting parts.
(5) Welding studs: half-orc fasteners consisting of main rods and nail heads or no nail heads, which are fixedly connected to parts or components by welding, so as to facilitate connection with other parts. (6) Assemblies and connection pairs: Assemblies refer to a kind of fasteners that make up the supply, such as certain types of equipment screws and flat pads; connection pairs refer to certain types of special anchor bolts, nuts and seals. A type of fastener that is composed of rings, such as high-strength large hexagonal head bolts for steel frame structures.
What are the surface treatment methods of fasteners?Surface treatment is the whole process of producing a soil layer on the surface of the workpiece according to a certain method, and its significance is to endow the product with a beautiful surface. The actual effect of corrosion resistance, the surface treatment methods of fasteners are all attributed to the following methods:
1. Electroplating. Electroplated metal material is allowed to precipitate and deposit on the part. Generally, electroplating includes hot-dip galvanizing, copper, nickel, chromium, copper-nickel alloy, etc., and sometimes blackening (bluening) and phosphating treatment are also involved.
2. Hot-dip galvanizing is carried out by immersing carbon steel parts in a bath of molten zinc at a temperature of about 510°C. The effect is that the iron-zinc alloy material on the surface of the cast iron gradually becomes the passivated zinc on the outer surface of the product. Hot-dip aluminizing is a similar process.
3. Mechanical plating impacts the surface of the product through the particles of the coated metal material, and sprays the coating onto the surface of the product. Generally, the electroplating method is mostly used for screws, but hot-dip galvanizing is used for electric power engineering, high-speed roads and other outdoor hexagonal wood screws; the cost of electroplating is generally 0.6-0.8 yuan per kilogram, and hot-dip galvanizing is generally 1.5-2 yuan / kg, the cost is higher.