A clamp comprising a plurality of pivotally related members and a plurality of jaw elements, each secured at the yoke portion thereof to a pivotally related member. From the free ends of each of the leg portions of the jaw element immediately below the uppermost jaw element are flat extension members, each extension member having two flat portions. The first portions extend upwardly from the jaw element immediately below the uppermost jaw element to a location above the uppermost jaw element. The second portion is essentially perpendicular to the first portion and located above the uppermost jaw element and aligned with the uppermost jaw element for clamping engagement with a work piece. This clamp is particularly useful for metal constructions which have a lip.