【Summary】Generally we use most of the fasteners belong to the type of general-purpose parts, its standard type is still quite high, the common fastener parts are the following 12 kinds:
Generally we use most of the fasteners belong to the type of general-purpose parts, its standard type is still quite high, the common fastener parts are the following 12 kinds:
1, the washer: the shape of a flat ring-shaped class of fasteners. Placed in the bolt, screw or nut support surface and connected parts between the surface, playing a role in increasing the contact surface area of the connected parts, reduce the pressure per unit area and protect the surface of the connected parts from damage; another type of elastic washer, can also play a role in preventing the nut back loose.
2, retaining ring: for installation in the machine, equipment, shaft groove or hole groove, playing a role in preventing the shaft or hole on the parts to move around.
3, pin: mainly for parts positioning, some can also be used for parts connection, fixed parts, power transmission or lock other fasteners.
4, rivets: by the head and nail rod of two parts of a class of fasteners, used to fasten the connection of two parts with through holes (or components), so that it becomes a whole. This form of connection is called riveted connection, referred to as riveting. It is a non-removable connection. Because in order to make the two parts connected together separate, the rivets on the parts must be destroyed.
5, combination parts and connection vice: combination parts refers to a combination of supply of a class of fasteners, such as a machine screw (or bolt, since the supply of screws) and flat washers (or spring washers, lock washers) combination supply; connection vice refers to a special bolt, nut and washer combination supply of a class of fasteners, such as steel structures with high-strength large hexagonal head bolt connection vice.
6, welding nail: due to the light energy and nail head (or no nail head) constitutes a different type of fastener, with welding methods to connect him fixed in a part (or member) above, so as to connect with other parts again.
7, bolt: by the head and screw (with external thread of the cylinder) two parts of a class of fasteners, need to cooperate with the nut, used to fasten the connection of two parts with through holes. This form of connection is called bolt connection. If the nut is screwed down from the bolt, there can make the two parts apart, so the bolt connection is a removable connection.
8, stud: no head, only the two ends are external threads of a class of fasteners. When connected, one end of it must be screwed into the parts with internal threaded holes, the other end through the parts with through holes, and then screwed on the nut, even if the two parts are fastened connected into a see the whole. This form of connection is called a stud connection and is also a removable connection. Mainly used for one of the connected parts thickness is larger, require compact structure, or because of frequent disassembly, should not use the occasion of bolt connection.
9, the nut: with internal thread hole, the shape is generally shown as a flat hexagonal column, but also a flat square column or flat cylindrical, with bolts, studs or machine screws, used to fasten the connection of two parts, so that it becomes a whole.
10, wood screws: also similar to machine screws, but the threads on the screw for special wood screws with ribbing, can be screwed directly into the wooden components (or parts), used to connect a metal (or non-metal) parts with a through hole and a wooden component fastened together. This connection is also a removable connection.
11, screws: also by the head and screw two parts of a class of fasteners, according to the use can be divided into three categories: machine screws, fastening screws and special purpose screws. Machine screws are mainly used for a fastening threaded hole parts, and a fastening connection between parts with a through hole, without the need for a nut with (this form of connection is called a screw connection, also belongs to the removable connection; can also be used with a nut with a fastening connection between two parts with a through hole.) Fixing screws are mainly used to fix the relative position of two parts. Special-purpose screws, for example, have lifting ring screws for lifting parts.
12、Self-tapping screws: similar to machine screws, but the threads on the screw are special threads for self-tapping screws. Used to fasten the connection of two thin metal components, so that it becomes a whole, the components need to be made in advance small holes, due to the high hardness of this screw, can be directly screwed into the holes of the components, so that the components form a response to the internal threads. This form of connection is also a removable connection
Strength grades are classified according to mechanical properties. According to the relevant standards, the bolt performance grade is divided into 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and more than 10 grades, of which 8.8 and above bolts made of low-carbon alloy steel or medium carbon steel and heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade number has two parts consisting of numbers, which indicate the nominal tensile strength value of the bolt material and the flexural strength ratio. For example.MORE +