●The attachment and detachment of the screw can be freely conducted and finishing is uniform with simple construction.●For installation of lighting fixtures, audio equipment and shelving brackets to hollow walls.●Nominal Designation of Thread:M4●Outer Diameter (mm):6.7●Screw Length (mm):52●Applicable Board Thickness (mm):17 to 23●Pilot Hole Diameter (mm):9●Steel●Surface treatment: Trivalent chromate treatment
