What's the difference between socket head cap screws? It's indispensable for industrial design

       The so-called hexagon socket head bolt refers to the hexagon socket head shape, which can also be called hexagon socket head screw, hexagon socket head screw and hexagon socket head screw.

Hardness and properties of hexagon socket

In general, the commonly used hexagon socket bolts are grade 4.8, grade 8.8, grade 10.9, grade 12.9, etc. In general, different grades of hexagon socket head bolts are selected according to different requirements, so as to play a more beneficial role in bolt performance. Today, I'd like to talk with you about the hardness grades of hexagon socket bolts.

Hardness grade

According to the hardness, carrying force and yield strength of screw wire, there is a grade classification for hexagon socket bolts, which is the grade of hexagon socket bolts. For different products and materials, it is required to have different grades of hexagon socket bolts corresponding to them.
Hexagon socket head bolts are classified into ordinary and high-strength bolts according to their grade strength. Ordinary hexagon socket bolts refer to grade 4.8 and high-strength hexagon socket bolts refer to grade 8.8 and above, including grade 10.9 and grade 12.9. Grade 12.9 hexagon socket bolts generally refer to black hexagon cup head screws with knurled and natural color and oil.
The performance grade of hexagon socket bolts for steel structure connection is divided into more than 10 grades, including 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9 and 12.9, among which the grade 8.8 and above are collectively referred to as high-strength bolts, the bolt material is low-carbon alloy steel or medium carbon steel and is heat treated, and the rest are generally referred to as ordinary bolts. The bolt performance grade mark consists of two parts of numbers, which respectively represent the nominal tensile strength value and yield strength ratio of bolt material.
 

Performance level

The bolt performance grade mark consists of two parts of numbers, which respectively represent the nominal tensile strength value and yield strength ratio of bolt material.

Bolts of property class 4.6, meaning:

1. The nominal tensile strength of bolt material reaches 400MPa;
2. The yield strength ratio of bolt material is 0.6; the nominal yield strength of bolt material is 400 × 0.6 = 240mpa.
The performance grade is 10.9 high-strength bolt, and the material can reach:
1. The nominal tensile strength of bolt material is up to 1000MPa;
2. The yield strength ratio of bolt material is 0.9; the nominal yield strength of bolt material is 1000 × 0.9 = 900MPa.
The meaning of performance grade of hexagon socket head bolt is the international general standard. For bolts with the same performance grade, the performance is the same regardless of the difference of material and place of origin. Only the performance grade is selected in design.
With different grades, the prices in the market must be different. Generally, the price of high-strength socket head bolts is much higher than that of common socket head bolts. In the market, there are generally 4.8, 8.8, 10.9 and 12.9 grades.