In addition to delayed time fracture, bolt fracture also has fracture modes such as fatigue fracture, impact fracture, and ductile fracture. The appropriate safety factor must be confirmed through strength calculations and experiments. So, what are the reasons for the breakage of bolts? The following maijin will introduce in detail. Relatively high precision can only be obtained with sufficient theoretical understanding of the safety factors of fatigue fracture and impact fracture, and through several months of experimental measurement. In addition to special-purpose bolts, there are 15 types of general bolts with outer diameters ranging from M4-M36, but most of them are M10-M20. The nominal length of the screw is 12-95mm. About 250 different types of bolts for excavators and about 130 types of screws for steam excavators. Most of the bolts used are hexagon bolts, in addition to hexagon socket bolts, flange bolts, hook bolts, etc., there are no special shape bolts. In the past, the bolts and the corresponding gaskets were independently managed, and the matching bolts developed later are flange bolts composed of gaskets. The standard parts are produced and processed using composite bolts, which can manage the serial numbers of the bolts and gaskets, reduce the part number, miniaturize the gaskets, and avoid the problem of fewer gaskets. In order to prevent bolts from rusting and bonding, surface treatment must be carried out on the bolts. Hexavalent chromium-based passivators were used in hot-dip galvanizing of screws in the past, but they were all discontinued after it was found that hexavalent chromium had negative effects on human health. The above is about the content we recommend to you now, and the relevant information about a large number of standard parts. Please pay attention to our website for a long time.