Views: 50 Author: Site Editor Publish Time: 2023-11-01 Origin: Site
The so-called hexagon bolts are bolts with a cylindrical head in the shape of a hexagon, which can also be called hexagon socket head screws and hexagon socket cylindrical head screws.
Many people have questions again, why is it designed as a hexagon, not a quad, pentagon or other shapes? Hexagonal screws can be graphically restored by screwing 60°. If the space is relatively small, as long as the wrench can be screwed 60 ° can be installed on the screws, which is in the screwing angle and the side length of the mutual compromise after the product.
If it is a square, the side length is long enough, but to screw 90 degrees to graphic restoration, not suitable for small space installation; if it is octagonal or decagonal, graphic restoration of the angle is small, but the side length of the force is also small, easy to grind round.
If it's a screw with an odd numbered side length, then the two sides of the wrench are not parallel, and in the very early days there were only forked wrenches with flared openings in the heads of the odd numbered side lengths, which didn't seem to be suitable for powering the wrench.
Hexagon socket head hardness and performance
In general, we commonly used hexagon socket head bolts are 4.8 grade, 8.8 grade, 10.9 grade, 12.9 grade and so on. In general, according to different needs to choose different hexagonal bolt grade, so as to play a more favorable role in the performance of the bolt. Today, tight business network to talk to you about the hardness level of hexagon bolts are.
Hardness level
Hexagon socket head bolts according to the hardness of the screw wire, carrying tension, yield strength, etc. There is a grade classification, that is, the level of hexagon socket head bolts, hexagon socket head bolts are what level. Different products and materials, the requirements of different grades of hexagonal bolts and their corresponding.
Hexagon socket head bolts are divided into ordinary and high strength according to the level of strength. Ordinary hexagon socket head cap screws are 4.8 grade, high strength hexagon socket head cap screws are 8.8 grade or above, including 10.9 grade and 12.9 grade. 12.9 grade hexagon socket head cap screws are generally referred to as knurled, black hexagon socket head cap screws with oil in the original color.
Steel structure connection with socket head cap screw performance grade 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and so on more than 10 grades, of which 8.8 and above are collectively referred to as high-strength bolts, bolts made of low-carbon alloy steel or medium-carbon steel and heat-treated, and the rest of the commonly referred to as ordinary bolts. Bolt performance level labeling has two parts of the digital composition, respectively, that the nominal tensile strength of the bolt material value and the value of the flexural strength ratio.
Performance grade
Bolt performance grade marking has two parts of the number, respectively, indicating the nominal tensile strength of the bolt material and flexural strength ratio value.
Performance level 4.6 grade bolts, the meaning of which is:
1.the nominal tensile strength of the bolt material up to 400MPa level.
2.the bolt material yield strength ratio of 0.6; bolt material nominal yield strength of 400 × 0.6 = 240MPa level.
Performance level 10.9 high-strength bolts, the material after heat treatment, can reach:
1.bolt material nominal tensile strength of 1000MPa level.
2.bolt material yield strength ratio of 0.9; bolt material nominal yield strength of 1000 × 0.9 = 900MPa level.
Hexagon socket head bolts performance level of meaning is the international standard, the same performance level of bolts, regardless of the difference between its material and origin, its performance is the same, the design of only the performance level can be selected.
Different grades, the market price is certainly different. General high-strength hexagon socket head bolts is certainly higher than the price of ordinary hexagon socket head bolts. In the market generally use more or 4.8 grade, 8.8 grade, 10.9 grade, 12.9 grade these four. Fasteners.com currently provides 8.8 grade, 10.9 grade, 12.9 grade, 14.9 grade hexagon socket head cap screws.
Advantages of using hexagonal bolts
1. can withstand greater load.
It has six stress surfaces, compared with only two surfaces of the word screws and cross-shaped screws more bear screwing.
2.in use can be buried head treatment.
That is, the entire nut is sunk into the inner workpiece, can keep the surface of the workpiece flat, beautiful.
3.easy to install.
Relative to the external hexagonal screws, hexagonal suitable for more assembly occasions, especially narrow occasions, so it is easy to assemble and repair, debugging is also convenient.
4.not easy to disassemble.
We usually commonly used tools such as adjustable wrenches, screwdrivers and dull wrenches, and disassembly of hexagonal bolts must use a special wrench. Therefore, the average person is not easy to disassemble. Of course, if you are hard, can be designed into a variety of strange structures, the problem is that the special wrench is not good manufacturing.
South of Ximingyang Village, Linmingguan Town, Yongnian District, Handan City, Hebei Province, China