Specifications and uses of Hexagon Flange Bolts
September 22, 2022
Specifications and uses of hexagon flange bolts
Flange bolts are integral bolts composed of hexagon head and flange plate (the gasket under the hexagon is fixed by the hexagon) and the screw (cylinder with external thread). It needs to be matched with a nut for tightening. Parts that securely connect two through-holes. Hexagon flange bolts are particularly common industrial equipment and appliances used in the industry. Today we want to talk about the basic specifications and uses of hexagonal flange bolts.
GB5787 Hexagon flange bolts
1. About Hexagon Flange Bolts
Hexagon bolts are the most widely used type of bolts. Its grade A and grade B bolts are used for important occasions where assembly accuracy is required, and where they are subjected to large shock, vibration or alternating loads. The C-grade bolts are used for occasions where the surface is relatively rough and the assembly accuracy is not required. The threads on the bolts are generally ordinary threads. The West Asian ordinary thread bolts have better self-locking properties and are mainly used on thin-walled parts or in situations where they are subjected to shock, vibration or alternating loads. General bolts are made of partial threads, and full-threaded bolts are mainly used for bolts with short nominal lengths and occasions requiring longer threads.
The use of hexagonal flange bolts eliminates the need to install flat washers and spring washers, because the upper flat washer is to increase the contact of the joint surface, and the upper spring is to increase the self-locking function. With flange bolts, the joint surface contact has been increased. Adding springs will reduce the contact surface and unevenness.
2. Specifications of hexagonal flange bolts
GB/T5789-1986 Hexagon Flange Bolts, Enlarged Series, Class B
GB/T5790-1986 Hexagon Flange Bolts Enlarged Series Thin Rod Class B
GB/T16674.1-2004 Hexagon flange bolts small series
GB/T16674.2-2004 Hexagon flange bolts, fine pitch, small series
Hexagon flange bolt national standard GB/T16674.2-2004
The standard stipulates that the thread specification is M8×1-M16×1.5, fine thread, the performance grade is 8.8, 9.8, 10.9, 12.9 and A2-70, and the product grade is A-grade small hexagonal series fine thread
The marking method is stipulated in GB/T1237
Thread specification d=M12×1.25, fine thread, nominal length L=80mm, F type or U type can be selected by the manufacturer, the performance grade is 8.8, the surface is oxidized, and the product grade is A grade of small hexagonal series hexagonal flange Marking of face bolts
Bolts GB/T16672.2 M12×1.25×80
Third, the use of hexagonal flange bolts
The head of the hexagonal flange bolt is composed of a hexagonal head and a flange surface. Its "support area to stress area word ratio" is larger than that of ordinary hexagonal head bolts, so this kind of bolt can withstand higher pre-tightening force and prevent The loose performance is also good, so it is widely used in automobile engines, heavy machinery and other products. The hexagonal head has a hole and a slotted bolt. When in use, the bolt can be locked by a mechanical method, and the anti-loosening is reliable. Hexagon flange bolts have the characteristics of accurate decoration and strong endurance, so they are widely used. They are widely used in highway and railway bridges, including industrial and civil buildings, cranes, excavators and other heavy machinery. With the changes in market demand, various new types of hexagon flange bolts have also been derived. For example, cross groove concave and convex hexagon head bolts are supplements to hexagon flange bolts.
Fourth, the basic classification of flange bolts
1. Hexagon head screw with hole bolt
The cotter pin hole is made on the screw to pass through the wire hole, and mechanical loosening is adopted to prevent loosening reliably.
2. Hexagon head reaming hole bolts
Bolts with hinged holes can accurately fix the mutual position of the linked parts, and can withstand shearing and extrusion generated in the transverse direction
3. Cross recessed hexagon head bolts
Easy to install and tighten, mainly used for light industry and instrumentation with less load
4. Square head bolt
The size of the square head is larger, and the force-bearing surface is also larger, which is convenient for the wrench to clamp its head, or rely on other parts to prevent rotation. Can also be used in parts with T-slots to adjust bolt position. Class C square head bolts are often used on relatively rough structures
5. Countersunk head bolts
The square neck or tenon has the function of anti-rotation, and is mostly used in the occasions where the surface of the connected parts is required to be flat or smooth.
6. T-slot bolts
T-slot bolts are suitable for applications where the bolts can only be connected from one side of the connected parts. Insert the bolt into the T-slot and then turn it 90 degrees, so that the bolt cannot be disengaged; it can also be used in occasions with compact structure requirements.
7. Anchor bolts are specially used for pre-embedded concrete foundations and joint bolts for fixing the bases of machines and equipment. They are mostly used in places and tooling that need to be frequently disassembled and connected.
8. High-strength bolts for rigid grid bolts and ball joints
High strength, mainly used for highway and railway bridges, industrial and civil buildings, towers, cranes.
The basic classification of several new hexagonal flange bolts is specially introduced above. These are made according to the latest market demand and have their specific usage scenarios. For example, T-slot bolts can be well connected to different styles. At the same time, these parts can also be used as an independent entity, such as each section or connection in the railway, which can move freely, so as to avoid dead knots in the connection and affect future maintenance and operation. It is widely used in relatively compact connections. in an industrial environment.
