The most important meaning of China Fasteners hardness is to resist the friction during assembly or the role in mechanical applications. For thread forming and thread cutting self-tapping screws, because it uses the internal extrusion or tapping from the mating hole Thread, so obviously, its hardness must be higher than the hardness of the mating assembly. If this is not the case, the self-tapping thread will be deformed or damaged during assembly, causing it to fail to screw in. Two different hardness materials can be It is clearly separated, such as clay and steel. If you want to screw a steel thread forming self-tapping screw into the clay, because the clay is soft and easy to deform, of course it is easy to screw in. Next, if If you want to screw a thread forming self-tapping screw made of clay into steel, you will find that you can't get it in. Therefore, the thread forming self-tapping screw must be harder than the mating workpiece.
In some operating situations, fasteners will also be used on the bearing surface. Especially for some screws with shoulders, the hardness is only a few important bearing parts but it is very important. These bearing surfaces must have sufficient hardness to Undertake the excessive friction that increases rapidly and accumulates during assembly to ensure the function after assembly and reduce the amount of maintenance. In this case, we take clay and steel as examples. Because steel is harder than clay, steel used as a fastener for movement is better than The clay has been used for a long time.
Another importance of Full Threaded Stud is that the hardness of the material is directly related to the tensile strength, shear strength and ductility of the material. When the hardness increases:
- The tensile strength is increased.
- Increased shear strength.
- Reduced ductility.