PURPOSE: To provide a single universal hand tool provided with a jaw of remarkable structure which is capable of surely holding workpieces of various shapes.

CONSTITUTION: A hand tool 10 is provided with a movable second jaw element 14 and an immobile jaw element 16, and when a screw member 24 is turned, a gap between the movable jaw 14 and the immobile jaw 16 is adjusted. In a center part 46 of the immobile jaw 16, a recess 54 is formed of first and second contact parts 41, 43 and a third contact part 45 therebetween. On the other hand, an arc-like projection 56 is provided on the movable jaw 14, and a workpiece is engaged with the first and second contact parts 41, 43 and the arc-like projection 56 when the workpiece is positioned between the recess 54 and the projection 56.