Reages for cracking in the manufacturing process of shaft parts can be analyzed from multiple aspects. The following is an analysis of the causes of cracking in shaft parts, represented and summarized by points: (1) Material quality issues: (2) Forging defects: such as pores, scars, inclusions, etc. that may exist in the material during forging, which can affect the mechanical and processing properties of the material, leading to cracking in shaft parts during subsequent processing or use. 2. Inclusiones materiales, libertates, segregationes brittles, etc.: Si haec defectus non sunt eliminata aut meliora in processione, defluxerunt principium anuli et erunt fontes fracturarum. Manufacturing process issues: 2. Uneven temperature: During the manufacturing process, if the temperature is not properly controlled, it may result in uneven temperature distribution, which may cause uneven stress distribution inside the material and lead to cracks at stress concentration points Excessive residual stress: Improper grinding, heat treatment, and assembly can cause residual stress. When these stresses exceed the strength limit of the material, it may lead to cracking of shaft components Excessive surface roughness: Excessive surface roughness may increase stress concentration on the parts, leading to cracking Design reason: 1. Unreasonable wall thickness design: If the wall thickness design of shaft parts is too thin or too thick, it may cause the parts to crack during processing or use. 2 Unreasonable structural design: If the structural design is too complex or there are stress concentration areas, it may increase the risk of component cracking Improper selection of machining tools: If the selected machining tool does not match the machining requirements of the part, it may also lead to cracking the part during the machining process Problemas calefactionis: 2. Improper heat treatment: Improper control of parameters such as quencing temperature and time may lead to uneven material structure, excessive internal stress, and other problems, thereby causing cracking Non potest facire relief stressi ante extinguere: Exemplo, si fraudulentum crankshaft fabricatum ex 45 steel a non subiectus est ad relief stress is annealing ante extinguere, potest causare stressum generatum ex extinguinatione superlapere cum stresso existente in angulo originalo, excedere limitum fortitudinis materiae et causam crackinga Factores utilizae et conservationis: 1. excessiva carga: excessiva carga in portantibus potest fregere partes portantes. 2 Improper operatio et maintenatio, sicut improper methodos congregationis et procedentibus, aut deficientia necessitatis maintenationis et upkeep dum utilitate, potest inducere ad fractionem componentium shaft.