Spax Countersunk Wood Screw Pozi Head 5 x 100mm is suitable for using with softwood, hardwood, chipboard and MDF. The screws have ribs and tucks on the head to self countersink into the wood without surface damage. These wood screws have a deep thread with a sharp point for a stronger and tighter fit. The reinforced collar reduces any snapping of the screw, and a 4cut point means that no pre-drilling is needed, allowing the screw to be used closer to the edge of the material without any splitting.