The material of the tower container anchor bolts is Q345. How to choose the matching nuts?
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The material of the tower container anchor bolts is Q345. How to choose the matching nuts? The standard GB 799-88 for anchor bolts only has level 3.6. How do you usually choose?
This post was last written by li* Edited by nji on 2019-1-18 11:46 We generally choose nuts with one grade higher strength than bolt materials. For Q235, we choose grade 4.6 nuts. The meaning is: 1. The nominal tensile strength of the nut material reaches 400MPa. 2. The yield strength ratio of the nut material is 0.6. 3. The nominal yield strength of the nut material reaches 400×0.6=240MPa.
This post was last edited by Gu Xicun on 2019-1-18 16:00 In general, not only anchor bolts, but also flange bolts have this idea. Bolts are one level higher than nuts or the same level. 2# explains the meaning of level numbers very thoroughly.
Generally, bolts are stronger than nuts, and the strength grade of nuts must be lower than that of bolts. If the nut grade is higher than that of bolts, the bolt threads will be damaged after tightening during installation. Bolt and nut grades https://bbs.hcbbs.com/thread-234975-1-1.html (Source: Haichuan Chemical Forum Network)
I have seen many places explaining that bolts are a higher grade than nuts.
Commonly used bolts and nuts pairing grade 4 nuts 3.6, 4.6 , 4.8 (>M16) bolts, grade 5 nuts, 3.6, 4.6, 4.8 (≤M16) bolts, 5.6, 5.8 bolts, grade 6 nuts, 6.8 bolts, grade 8 nuts, 8.8 bolts, grade 9 nuts, 8.8 bolts, 9. 8 (≤M16) bolts, grade 10 nuts, 10.9 bolts, grade 12 nuts, 12.9 (≤M39) nuts. This is recommended by the GB/T3098.2 standard. Grade 5 nuts match grade 3.6 and 4.6 bolts.
The following table comes from standard GB/T3098.2
The material grade of nuts is generally one grade higher than that of bolts. For example, if bolts are 4.8, then nuts 5 or 6 will be fine.