Dagger-Lok square drive flat head wood screw w/nibs type 17 coarse. Flat heads are available with nibs under the head and a type 17 point for attaching ash, alder, beech, oak, mahogany, walnut, rosewood, teak, MDF board, OSB board and other hardwoods.
 
                 
             
             
                 
                 
                 
                 
                 
                 
                 
                