Abstract: An alignment clamp is disclosed for uses such as welding adjacent plates. The clamp utilizes a strap which passes through a gap between the adjacent plates. The strap is attached at one end by a plate like clamp member which is to be located on one side of the welded plates. The strap connects to a clamp member on the opposite side. The second clamp member is located above the plate to be clamped. It is on freely movable guide posts spaced apart from a bearing plate. A tapered wedge is driven between the second clamp member and the bearing plate. The tapered wedge separates the two and pulls the strap taut. When it is taut, it levels and temporarily connects the adjacent plates held by the clamp to permit welding in the gap between the adjacent plates, and is thereafter disassembled to enable the removal of the clamp to close the gap by welding.