Patent attributes
A screw includes a shank with an outer periphery, a head connected to the shank, and thread convolutions spiraling around the shank in a right-hand direction. The outer periphery defines opposite first and second peripheral envelope surfaces. A cutting slot unit is formed on the shank and arranged on the first peripheral envelope surface. The cutting slot unit includes a first cutting slot with two first edges and a second cutting slot with two second edges. The first edge extends in an extension direction opposite to the right-hand direction. One first edge of the first cutting slot is parallel to one second edge of the second cutting slot. The opposite extension of the cutting slot unit assists the screw in screwing quickly, attains quick removal of chips, and increases the fastening effect by pressing chips downwards.