The most important significance of fastener hardness is resistance to friction during assembly or in mechanical applications. Its hardness must be higher than the hardness of the assembled assembly.
If this is not the case, the blind rivet countersunk will be deformed or damaged during assembly.
The material hardness of open end blind rivet countersunk head is directly related to the tensile strength, shear strength and ductility of the material. When the hardness increases, the tensile strength increases, the shear strength increases, and the ductility decreases.
The open end blind rivet countersunk head has a relatively high hardness and a high tensile strength and shear resistance.
In some applications, fasteners are also used to support the face, especially for some shoulder screws. The hardness is only important for several important receiving parts but it is very important. These bearing surfaces must have sufficient hardness to withstand the excessive friction that builds up quickly and accumulates to ensure post-assembly functionality and reduce maintenance.