1. Strength grade of stainless steel bolts
1. What are stainless steel bolts
Stainless steel bolts are very resistant bolts that can resist corrosion from acids, alkalis and salts. And the different basic ingredients have different resistance points, so there are also cases where they are rust-resistant but not acid-resistant. In our daily lives, the stainless steel bolts we use are divided into 304, 316 and other models.
, Strength grade
①The performance grade of common stainless steel bolts is 8.8, which means the tensile strength is 800MPa and the yield strength is 640MPa. Stainless steel bolts can be divided into 10 grades from bolts to studs, from 3.6 to 12.9. This decimal point does not represent the decimal point in mathematics. The left side of the decimal point represents the strength limit of the material, and the right side of the decimal point represents the ratio of the yield limit to the tensile limit.
②Nuts are also divided into 7 grades, from 4 to 12. The larger the number, the minimum stress that the nut can withstand.
③According to the bolt pattern, the external thread can be divided into 1A, 2A and 3A, and the internal thread can be divided into: 1B, 2B and 3B. As the number increases, the grade is higher and the fit is tighter.
1A, 1B: The grade with tightness to be improved, only the tolerance fit of internal and external threads is applicable.
2A, 2B: The most commonly used thread tolerance grade using British series firmware.
3A, 3B: This level has the tightest screw fit and is mainly used in some safety-critical designs.
④Thread grade, divided into external thread and internal thread. External thread is divided into: 4H, 6H and 6G; internal thread is divided into: 5H, 6H and 7H. The thread matching is also preferably h/g, h/h or g/h. This combination of bolts has strong firmness.
3. Types of stainless steel bolts
There are many types of stainless steel bolts, even dozens of them, and different specifications have different purposes. For example: hexagonal bolts, hexagonal set screws, hexagonal screws, cross-slotted flat head self-tapping screws, hexagonal nuts, butterfly nuts, etc.
