Stainless steel bolt strength grade Stainless steel bolt type

1. Strength grade of stainless steel bolts

The performance level of stainless steel bolts 8.8 refers to the tensile strength limit of the material is 800MPa, and the yield limit is 640MPa.

The performance grades of stainless steel bolts, studs and studs are divided into 10 grades: from 3.6 to 12.9. The number before the decimal point represents 1/100 of the tensile strength limit of the material, and the number after the decimal point represents 10 times the ratio of the yield limit of the material to the tensile strength limit.

The performance level of the nut is divided into 7 levels, from 4 to 12. The number roughly represents 1/100 of the minimum stress that the stainless steel nut is guaranteed to withstand.

For unified inch threads, there are three thread grades for external threads: 1A, 2A and 3A, and three grades for internal threads: 1B, 2B and 3B, all of which are clearance fits. The higher the level number, the tighter the fit.

1, 1A and 1B grades, very loose tolerance grades, which are suitable for tolerance matching of internal and external threads.

Classes 2, 2A and 2B are the most common thread tolerance grades specified for the inch series mechanical stainless steel fasteners.

Class 3, 3A and 3B, screwed to form the tightest fit, suitable for stainless steel standard parts with tight tolerances, and used for key safety designs.

Metric thread, external thread has three thread grades: 4h, 6h and 6g, internal thread has three thread grades: 5H, 6H, 7H. Thread fit is best combined into H/g, H/h or G/h. For refined fastener threads such as bolts and stainless steel nuts, the standard recommends using 6H/6g fit. (Guide: Fastener selection principles and methods)

Carbon steel: The strength grade marking code consists of two numbers separated by ?. The meaning of the number before? In the mark code indicates the nominal tensile strength, such as 4 in 4.8 indicates 1/100 of the nominal tensile strength of 400N/MM2. The meaning of? In the mark code and the number part after the point indicates the yield strength ratio, that is, the ratio of the nominal yield point or the nominal yield strength to the nominal tensile strength. For example, the yield point of grade 4.8 products is 320N/mm2.

The strength grade mark of stainless steel products consists of two separate parts. The front symbol in the logo code indicates the material. Such as: A2, A4 and other signs indicate strength, such as: A2-70

Carbon steel: Metric stainless steel bolt mechanical performance grades can be divided into: 3.6, 4.6, 4.8, 5.6, 5.8, 6.8, 8.8, 9.8, 10.9, 12.9, a total of 10 performance levels

Types of stainless steel bolts

There are many types of stainless steel bolts, even dozens of types, and different specifications, the purpose of use is also different. For example: Hexagon socket bolts, Hexagon socket tip set screws, Hexagon socket head screws, Cross recessed flat head tapping screws, Hexagon nuts, Wing nuts, etc.

Summary of the article: The above is all about the strength grade of stainless steel bolts and the types of stainless steel bolts. I don't know, but I was shocked at first sight, a small stainless steel bolt actually has so much cold knowledge. Therefore, when decorating a new house, everyone should pay attention to those inconspicuous little materials. Don't let us use some fasteners that use bolts for connection because we don't pay attention to the practicality of bolts and let us use them for a few years.

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