Finding broken studs or bolts is one of the most unwanted scenarios we can think of, especially when working on cars and other mechanical equipment. Many people have tried to develop different methods to remove any broken bolt from their properties ranging from the cylinder guard on your motorcycle carburetor to the metal plates on your garage doors. Methods such as drilling and welding are now available on the Internet in response to the increase in cases of broken bolts.
The real question is: “What Causes a Broken Bolt?“
1. Getting too stressed
The word “excessive stress” is enough to understand this cause; however, there is more to it than that. There are 3 types of load experienced by the bolt: preload, service load, and tensile load. Preload refers to the internal stress that keeps the two gasket materials intact, while service load refers to the external factors that cause the gasket materials to exert separate stresses. Tensile load, on the other hand, refers to a static stress that pulls both ends of the bolt separately. Tightening and turning the nut regularly will increase the tensile load on the bolt. If the tensile load exceeds the tensile strength, the bolt will suffer permanent damage causing it to break. It is necessary to determine the appropriate amount of torque applicable to specific types of bolts to avoid excessive stresses.
2. Fatigue
Approximately 85% of all broken screw boxes are due to fatigue. All bolts, especially shear bolts, were designed to fail in due time. In other words, its efficiency is not for life. This can be explained by going back to preload and service load. Each bolt or stud undergoes a preload and duty load cycle. Then fatigue is determined by how many load cycles a bolt can withstand. This is why most equipment manuals would suggest replacement of the bolts after one or two years, especially when the bolt is frequently exposed to stressors such as those from modeling equipment and forming machines. print.
3. Corrosion
Corrosion, on the other hand, refers to the effects caused by external elements such as chemicals excreted from nearby parts or exposure to incompatible metallic components. For example, bolts near the vehicle’s engine can leak oil and other engine fluids. These chemicals will cause the bolt to deteriorate over time, that is, chemical corrosion.
Another type of corrosion is when the bolt was used to join incompatible metal components. Due to incompatibility, the bolt deteriorates and could also break. This is what we call galvanic corrosion. Although corrosion is one of the main causes of broken bolts, it is still a rare case and can only be found in advanced metal industries such as mechanical engineering, mining, and construction.
Among these three, fatigue included most cases of broken bolts followed by excessive stress. Corrosion varies from situation to situation and rarely occurs. Taking these factors into account will help you keep your equipment efficient by preventing bolts from breaking.
