QC/T 518-2013 in English

本标准规定了汽车用螺纹紧固件紧固扭矩。
标准适用于符合以下条件，以控制扭矩方式进行的紧固：
---外螺纹件的机械性能符合GB/T 3098.1规定的8.8、10.9和12.9级；
---内螺纹件的机械性能符合GB/T 3098.2或GB/T 3098.4，且具有充分发挥螺纹连接副承载能力的强度；
---内、外螺纹件的六角对边尺寸符合GB/T 3104规定的标准系列；
---螺栓-螺母连接副以及螺栓-螺母以外的螺纹连接副；
---螺纹符合GB/T 196，螺纹精度不低于GB/T 197规定的6级；
---外螺纹件在紧固中承受轴向拉伸载荷；
---螺栓或螺钉的设计拉力采用屈服点σs或屈服强度σ0.2的90％。
本标准不适用于外螺纹件在紧固中承受压缩力的紧定螺钉、由外螺纹件攻出螺纹的自攻螺钉及木螺钉、采用弹簧垫圈或弹性垫圈的螺纹紧固件以及有效力矩型螺纹紧固件的紧固。

Scope

This standard specifies the tightening torque of threaded fasteners for automobiles. This standard applies to tightening by controlled torque that meets the following conditions:
　——The mechanical properties of external threaded parts comply with grades 8.8, 10.9 and 12.9 specified in GB/T 3098.1;
　——The mechanical properties of internally threaded parts comply with GB/T 3098.1. T 3098.2 or GB/T 3098.4, and has the strength to fully utilize the load-bearing capacity of the threaded connection pair;
　——the hexagonal dimensions of the internal and external threaded parts comply with the standard series specified in GB/T 3104;
　——the bolt-nut connection pair and Threaded connection pairs other than bolts and nuts;
　——Threads comply with GB/T 196, and thread accuracy is not less than level 6 specified in GB/T 197;
　——Externally threaded parts bear axial tensile load during tightening;
　——The design tensile force of bolts or screws is 90% of the yield point σs or yield strength σ0.2. This standard does not apply to set screws in which externally threaded parts bear compression force during tightening, self-tapping screws and wood screws tapped from externally threaded parts, threaded fasteners using spring washers or elastic washers, and effective torque types. Tightening of threaded fasteners.