A hand tool includes a tool shaft having a shank and a handle pivotally coupled together, and a tool head, which includes a socket defining a socket hole attachable to a locknut at a coaxial cable for fastening or loosening the locknut and a side opening for the passing of the locknut into or out of the socket hole, a driven structure located on an inner side of a receiving hole at one side of the socket hole, a transmission shaft coupled to the shank of the tool shaft and having a driving head located on one end thereof for engagement with the driven structure of the socket, and an elastic member stopped between the driving head and the socket such that when the socket reaches a predetermined torque value during operation, the driving head is moved axially away from the driven structure to compress the elastic member and to run idle.