Shear strength refers to the shear force that a unit bonding area can withstand when an adhesive joint fails, expressed in megapascals (MPa). According to the force application method during testing, shear strength is further classified into tensile shear strength, compressive shear strength, torsional shear strength, and bending shear strength, etc. Adhesives with different properties exhibit varying shear strengths. Generally speaking, tough adhesives have higher shear strength than flexible adhesives. Numerous tests have shown that the thinner the adhesive layer, the higher the shear strength.