GB/T 32076.4-2015 Active

This part of GB/T 32076 and GB/T 32076.1 specifies high-strength bolt and nut assemblies for thread sizes M12 to M36, large hexagonal series, with performance grades of 10.9/10, HV type, and preload connection. The bolt and nut assemblies designed in this part allow a preload of ≥0.7Rm×A1)s, and the extension performance is primarily ensured by the plastic deformation of the threaded joint. For this reason, the parts should have the following characteristics: -- The nut height is approximately 0.8D; -- Bolts with a short thread length. The bolt and nut assemblies specified in this part should also include washers in accordance with GB/T 32076.6. Note: To obtain satisfactory results, ensuring the correct use of bolts is very important. For methods of correct use, please consult or refer to relevant specifications. The preload adaptability test is described in GB/T 32076.2. This part applies to high-strength bolt assemblies for preload connection in industrial and civil buildings, bridges, tower structures, boiler steel structures, lifting machinery, and other steel structures. Appendix A provides the total clamping length and clamping length of bolt and nut assemblies. Appendix B gives a description of two application types of European steel structure bolt assemblies. 1) Rm is the nominal tensile strength, and As is the nominal stress area of the thread.