I would like to ask about the compatibility of hex head bolts and nuts according to HG/T20634-2009
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I have a question: regarding the pairing of hex head bolts and nuts as specified in HG/T20634-2009, 35CrMoA is used for fully threaded studs. Should nuts also be made of 35CrMoA according to the table? Isn’t it usual that nuts require a lower grade material?
I can’t upload pictures. What’s the problem?
In Table 3.3.1 on page p466, there are two inconsistencies: 35CrMo studs are used with 30CrMo nuts.
Thank you! However, Table 5.0.4 on page P439 shows that 35CrMo studs are used in combination with 35CrMo nuts, which is contradictory.
The grade strength and mechanical properties of studs and nuts can be achieved through subsequent heat treatment and quenching. In terms of grades, 35CrMoA material can be heat-treated to achieve grades 8.8, 10.9, and 12.9. Different grades have varying tensile strength, yield strength, reduction of area, elongation, and hardness. Nuts made of the same material retain their load-carrying capacity and resistance to torsional shear after heat treatment, and their hardness remains the same as well. Next, it depends on what type of flange the stud nut is used with; the surface treatment is then chosen based on the operating environment.