Abstract: A clamp for securing in proper relationship portions of a piece or sheet of material on opposite sides of a kerf or other separation. The clamp has a base block or part and a pressure block or part the two of which engage a sheet or pieces of material from opposite sides of a kerf therein or line of separation therebetween. The base block carries a blade which projects through the kerf or line of separation into a receiving slot or opening in the pressure block. By tightening fastening means such as a nut threaded on a screw projecting from the kerf blade, the base and pressure blocks may be drawn together in clamping relationship on opposite sides of a kerf or line of separation thereby holding in normal or coplanar relationship the juxtaposed sections separated from each other by the presence of a kerf or other form of separation.