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How to distinguish between high-strength nuts and ordinary nuts?



Many users do not know the difference between high-strength nuts and general nuts. In fact, they can be easily distinguished by understanding their standard and other characteristics. The so-called high-strength nut is a special bolt with high strength and high fatigue resistance used in special equipment or engineering. Of course, generally high-strength nuts are used with high-strength bolts to achieve better application.
We generally see that many bolts with M heads in the market are ordinary nuts, not high-strength nuts. The calibration side of the general hexagonal head nut is the following pattern M30, and M30 indicates the thread standard, that is, the inner diameter of the thread is 30mm. Grade 10 indicates the functional grade of the bolt, and tZn is the surface treatment method.
Other types of bolts also have their own expressions, but generally threaded bolts must be based on the original functional grade of "M":
The functional level of the nut is divided into 3, 4, 4, 5, 5.8, 6, 8, 10, 12 so many levels from small to large. This symbolic method means taking 10 as an example. 10 indicates 1/100 of the tensile strength of the bolt, which means that the tensile strength of this grade of bolt must reach the level of 1000MPa, which may be higher than 1000MPa in practice.
GB/T3098.1 rules the smaller tensile strength of this grade of bolts must be greater than 1040MPa. After the decimal point, the yield strength ratio is indicated, that is, the bolt's (yield strength/tensile strength)=0.9, that is, the yield strength=1000*0.9=900MPa. The yield strength of this grade of bolt must be higher than 900MPa to be qualified.
Generally, we call the nuts of the three grades of 8.8, 10.9, and 12.9 as high-strength nuts.
It should be noted that GB/T3098.1 does not give detailed values ​​of yield strength for these three grades of bolts. This is because for high-strength bolts 0.8 and 0.9 are the smaller yields regulated by this grade. Strength