The nut is a part that is screwed together with a bolt […]
The nut is a part that is screwed together with a bolt or a screw for fastening, and one component that must be used in all manufacturing machinery. The variety of nuts is divided into carbon steel and high strength depending on the material. Stainless steel, plastic steel and other major types. According to the product attributes corresponding to the country's different standard number is divided into ordinary, non-standard, (old) national standard, new national standard, American system, British system, German standard.
Hex nuts are classified into I type, II type and thin type according to the nominal thickness. Nuts of class 8 or higher are divided into two types, type I and type II.
Generally, the decimal number after the bolt grade is removed is the grade of the nut, the 8.8 bolt is equipped with the 8 grade nut, and the 10.9 bolt is matched with the 10 grade nut.
That is, the bolts and nuts have the same strength grade (the strength grades of bolts 8.8 and nuts 8 are the same, and the ".8" after the bolts indicates that the yield strength is 80% of the tensile strength.)
However, considering the use case, if the nut is not replaced properly, the bolt is easier to replace and can also be changed to the bolt 4.8 nut 5.
In some cases, the nut is lower than the bolt strength. The main reason is: The failure of the bolt is usually not easy to detect, sometimes it is sudden, and the nut failure is more easily found. Also consider the security aspect. This ensures that the life of the screw is longer than that of the nut when used in combination, and the cost is even lower and easier when the fastener is removed and replaced.