A screw includes a threaded shank and a head with a first surface. Communicating sockets formed in the first surface include a Pozi-type socket and a drive socket. The drive socket includes rounded portions, arched portions alternating with the rounded portions, and a conical portion connected to the rounded portions and the arched portions to define a first reference line and a second reference line parallel to a central axis of the head. The rounded portions are inclined outwardly from the first reference line, and the arched portions are inclined outwardly from the second reference line. Thus, a first room enclosed by the rounded portions and the arched portions increases gradually towards the first surface. By a combination of the above sockets, the head cooperates with different driving tools for delivering driving force efficiently and is more convenient to use.