Handan Chang Lan Fastener Manufacturing Co., Ltd. formerly Yongnian Tiexi Changhe fastener factory was large-scale standard fastener manufacturer in Yongnian District. The company is located in standard fastener distribution center of Hebei Yongnian, covering an area of 3,050 square meters, was close to Tianjin Port and Qingdao ports, export is very convinedtly. The company has multi position cold heading machine, model 12b, 14b, 16b, 24b, 30b, 33b; has hot forging machine, model has 200 tons, 280 tons, 500 tons, 800 tons;Has a variety of supporting equipment, including rolling machine, rolling machine, oil press, etc. for bolts, nuts, double stud bolts , foundation bolts and complete product testing equipment. With an experienced technical research and development team, high-quality management personnel and spacious production environment.Thin nuts and thick nuts in addition to the height of the hexagonal is not the same, other are the same, some installation environment space is not big enough, in order to facilitate installation, will be thin nut design, just can be stuck in the space. This is a last resort. But in some places, where there is no space limit, thin nuts are also designed, so why is this? If we want to know why thin nuts are still designed and used even though their torsion strength is not as good as thick nuts, we should first know the law and change of pretightening force and cycle times of nuts of different thickness.