Disclosed herein is a clamp for interconnecting two components of a support apparatus such as components of a shoring apparatus for concrete forming systems. A clamp member having a moveable jaw is received for pivotal movement in a housing that is secured to one of the components. A plurality of flutes disposed at an angle to the pivot axis of the clamp member are received in coacting recesses in the housing and a proximal cap maintains the desired position of the clamp member within the housing. Axial movement of the clamp member will pivot the swing arm and a coacting, moveable jaw toward a fixed jaw formed in the housing to releasably secure the clamp to the other component.