Abstract: A screw includes a head and a shank combined together. The head is formed with a circumference provided thereon with continuously arranged point-shaped ribs. When the circumference of the head is being locked into a wood piece, the ribs will function to carry out excavating to enable the screw to be locked into the wood piece comparatively easily.

Abstract: A screw head slot shaper includes a shank and a head slot molding member formed on an upper end of the shank. The shake can be of any shape and of a proper length. The head slot molding member has plural square layers, which respectively have different sizes. So a single screw head slot shaper can manufacture screws with a head formed with a single layer slot, a two-layered slot or a three-layered slot depending on demands. Thus many different tools may conveniently be used for driving screws with a head with a slot of a single or plural square layers.