A socket includes an inner lining detachably formed in an inner hole within the socket, with the inner lining formed therein with a differentially-sized torque recess including at least a large hexagonal hole defining a large diagonal distance (D1) between two diagonal points of the large hexagonal hole and a small hexagonal hole gradationally contracted inwardly from the large hexagonal hole and defining a small diagonal distance (D2) between two diagonal points of the small hexagonal hole, so that each inner lining may be provided for selectively engaging at least two differently-sized nuts (or bolts) for convenient and economic torquing purpose.