It can effectively prevent water leakage and seepage of the building structure, play a role in shock absorption and buffering, and also has a good fastening and sealing effect, so it is widely used in life.Square washers for construction should replace circular washers for wood construction and concrete floor applications; They are used with all fasteners for greater load distribution and bolt penetration through walls or wood.1. Expand the contact surface, reduce the stress concentration of the fastening force on the fastener, and prevent damage to the fastener. 2. Do not scratch the fastener when tightening the nut. 3. The flower pad and spring pad also have the function of preventing the nut from loosening.