Into soft wood, Small diameter screws can be driven directly without drilling a pilot hole. Without it, we also screw in screws into the faces of wood-based panels, e.g.. particle board. In all other cases, drill a pilot hole approximately equal in diameter 2/3 screw diameter. It is a good idea to coat the screw with plain soap – not fat. The soap film reduces friction between metal and wood, and at the same time, unlike grease, it will not stain the wood.