the base portion 26 and a pair of shoulders 34 at right angles to the flanges and coplanar with a perimeter p of the base see for example fig3 when the fastening member 22 is installed in the decking assembly the flanges 46 48 are positioned within grooves in the sides of the adjacent deck boards the flanges 46 48 have a height 32 that matches the grooves in the sides of the deck boards to ensure a secure fit as shown in fig3 the outer edges of the flanges 46 48 are curved also as shown in fig3 and 4 the crosspiece 28 has a planar upper surface 30 and planar lower surfaces 36 that are formed by the flanges 46 48 the planar upper 30 and lower 36 surfaces are perpendicular to the base 26 the outer surfaces 40 of the crosspiece flanges are parallel to the shank portion 18 of the fastener 12 and the outer surfaces of the base 26 the crosspiece 28 is substantially uniform about the longitudinal axis a thereby forming a substantially symmetrical clip the clip 16 can be of any material including metal or plastic or a combination of metal and plastic in an embodiment the clip can be injection molded plastic the clip can be formed.