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Fastener product knowledge and product related standards

fastener product knowledge and product related standards Abstract: the basic skills that should be mastered in the development of single chip microcomputer the selection of CNC drilling machines and milling machines compared with the first four with the guide Luoyang a private enterprise developed an automobile continuously variable transmission device inner cone edge grinding fried dough twist drill process experimental research the prospect of grinding processing facing the challenge of hard cutting absolute and relative coordinates of CNC machine tools Introduction to the development trend of precision machining and ultra precision machining and the maintenance and upkeep of strong current control system of CNC machine tools. The simplest way to upgrade ordinary machine tools to high-speed machines. Introduction to the principle of electric speed increaser frequency converter. Research on die casting die CAD system. Seiji Mori will appear in the 7th China international Electromechanical Products Expo sinu, but it has a simple operation interface. Merik 810d/840d concise debugging manual -- hardware description "China mold design classic" Laser robot system for cutting automotive hydroforming pipes market demand and development of CNC machining equipment for steel structures application example of programming of high-efficiency oilstone grinding device WEDM machine tool design of high-voltage motor intelligent test system based on PLC and configuration software PLC machine tool control technology is more economic significance product standards involve knowledge and connecting parts screw fastening fastening connection a class of mechanical parts are widely used fastening special There are many kinds of points, specifications, performance, uses, standardization, serialization, and versatility. National industry standards. Class I fasteners are called standard fasteners for short. Each specific fastener product specification, dimension, tolerance, weight, performance, surface condition, marking method, acceptance inspection, marking, packaging items

fasteners are a kind of mechanical parts used for fastening and connection, which are widely used Characteristics of fasteners: various varieties and specifications, different performance and uses, and a high degree of standardization, serialization and generalization. Therefore, some people also call a class of fasteners with existing national (industry) standards as standard fasteners, which are called standard fasteners for short

since the specifications, dimensions, tolerances, weight, performance, surface conditions, marking methods, as well as the specific requirements of acceptance inspection, marking and packaging of each specific fastener product are specified in several national (industry) standards, such as British system, German system and American system

fasteners are the most widely used basic mechanical parts. With China's entry into WTO in 2001, it has entered the ranks of international trade powers. China's fastener products are exported to countries all over the world, and fastener products from countries all over the world continue to flow into the Chinese market. As one of the products with large import and export volume in China, the realization of fasteners in line with international standards has important display and strategic significance for promoting Chinese fastener enterprises to go global and promoting fastener enterprises to fully participate in international cooperation and competition

fastener is the general term of a kind of mechanical parts used to firmly connect two or more parts (or components) into a whole. Also known as standard parts in the market

it usually includes the following 12 types of parts:

1 Bolt: a kind of fastener composed of head and screw (cylinder with external thread), which needs to be matched with nut to fasten and connect two parts with through holes. This connection form is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection is a removable connection

2. Stud: a kind of fastener with no head and only external threads on both ends. When connecting, one end of it must be screwed into the part with internal thread hole, and the other end must pass through the part with through hole, and then screw on the nut, even if the two parts are firmly connected as a whole. This connection form is called stud connection, which is also a removable connection. The purpose is to compress the contact part between the indenter or anvil and the experimental machine. It is mainly used in occasions where one of the connected parts is thick and requires compact structure, or bolt connection is not suitable due to frequent disassembly

3. Screw: it is also a kind of fastener composed of head and screw. It can be divided into three categories according to its purpose: machine screw, set screw and special purpose screw. Machine screws are mainly used for the fastening connection between a part with a threaded hole and a part with a through hole, without nut matching (this connection form is called screw connection, which also belongs to removable connection; it can also be matched with nuts, which is used for the fastening connection between two parts with a through hole.) The set screw is mainly used to fix the relative position between two parts. Special purpose screws, such as eyebolts, are used for hoisting parts

4. Nut: with internal thread hole, it is generally in the shape of flat hexagonal column, or flat square column or flat cylindrical. It is used to fasten and connect two parts into a whole with bolts, studs or machine screws

5. Self tapping screw: similar to machine screw, but the thread on the screw is a special thread for self tapping screw. It is used to fasten and connect two thin metal components to make them a whole. Small holes need to be made on the components in advance. Because this screw has high hardness, it can be directly screwed into the holes of the components to form a responsive internal thread in the components. This type of connection is also a removable connection

6. Wood screw: it is also similar to machine screw, but the thread on the screw is a special rib for wood screw, which can be directly screwed into wood components (or parts) to firmly connect a metal (or non-metal) part with a through hole with a wood component. This connection is also a detachable connection

7. Washer: a kind of fastener with flat circular shape. It is placed between the support surface of bolts, screws or nuts and the surface of connecting parts, which plays a role in increasing the contact surface area of connected parts, reducing the pressure per unit area and protecting the surface of connected parts from damage; Another kind of elastic washer can also prevent the nut from loosening

8. Retaining ring: it is installed in the shaft groove or hole groove of machine and equipment, and plays the role of preventing the parts on the shaft or hole from moving left and right

9. Pin: it is mainly used for positioning parts, and some can also be used for connecting parts, fixing parts, transmitting power or locking other fasteners

10. Rivet: a kind of fastener composed of head and nail rod, which is used to fasten and connect two parts (or components) with through holes to make them a whole. This connection form is called rivet connection, which is called riveting for short. It is connected with the non detachable part. Because to separate the two parts connected together, the rivets on the parts must be destroyed

11. Assembly and connecting pair: assembly refers to a kind of fastener supplied by combination, such as the combination of a certain machine screw (or bolt, self supplied screw) and flat washer (or spring washer, lock washer); Connection pair refers to a kind of fastener that combines some special bolts, nuts and washers, such as high-strength large hexagon bolt connection pair for steel structures

12. Welding nail: a heterogeneous fastener composed of light energy and nail head (or no nail head), which is fixedly connected to a part (or component) by welding, so as to connect with other parts

each fastener product should involve some standards of several aspects:

1) standards of fastener product size: specify that the product basically does not pay attention to quality and long-term benefits, so we cannot reach the content of size without sacrificing product quality; Products with threads also include the basic dimension of threads, thread ending, shoulder distance, undercut and chamfer, and the end dimension of external thread parts

2) standards for technical conditions of fastener products. Specifically, it includes the standards of the following aspects:

A) standards of fastener product tolerance: specifically specify the tolerances of product dimensions and geometric tolerances

b) standards for mechanical properties of fastener products: specify the marking method of product mechanical property grade and the contents of mechanical property items and requirements; For some fastener products, this content is changed to the content of product material performance or working performance

c) standards for surface defects of fastener products: specify the types and specific requirements of product surface defects

d) standards for surface treatment of fastener products: specify the types and specific requirements of product surface treatment

e) standards for fastener product test: specify the contents of the above performance requirements test

3) standards for fastener product acceptance inspection, marking and packaging: specify the qualified quality level and sampling plan of spot check items during product delivery acceptance, as well as the content of product marking methods and packaging requirements

4) standards for fastener product marking methods: specify the contents of complete product marking methods and simplified marking methods

5) standards for other aspects of fasteners: such as standards for fastener terminology, standards for fastener product weight, etc

based on all the above knowledge, I think you must have more understanding of fasteners, and you will also have a certain amount of help in developing your career. As the saying goes: only by knowing yourself and your enemy can you win every battle! What if people who are not familiar with products are important to success

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