Hard nuts need to deal with it? Yesterday, a customer asked to create a solid Division I screw Zhujing. Nuts, we all know, in general, we are using ordinary nuts, stainless steel nuts to do that, you want to do is carbon steel nuts, nut 4.8. Of course, if the need to add a hard nut deal with the case. In general, then, we called eight nuts, but did not say like, like screws, screw what 8.8, but can not say 8.8 nut, can only say eight nuts. 8 certainly need to add a hard nut processing, general 4.8 is certainly no need to add a hard nut processing. 8 nut nuts on top of the general will play an 8-word. Ordinary nuts are no words. Of course, eight nuts, be sure to use a good wire manufacturing. Through good after manufacture, in take heat treatment, hardening process. Hardness level so as to achieve 8.