To cut out an accurate connection easily by providing a reference line intended for aligning a substrate and side edge made up of side plates vertically rising from the perpendicular two sides of the substrate.

Screw holes 6 are made on the substrate 2 and the side plate of a brace connecting hardware 1. Reference lines, 4, 4, 4 are provided on the surface 2 of the substrate of the brace connecting hardware 1. The reference lines 4 are provided by inscribing broken lines. They may be, however, also given by printing. A peephole 5 is provided if necessary. To cut out the connection of a brace 7, the brace connecting hardware 1 is positioned by placing a reference line 4 on the side edge of a bracing member 7' and the brace connecting hardware 1 on the bracing member 7' and drawing cutting lines 12 along the edges on the side plate side using the brace connecting hardware 1 as a ruler with a pencil. And then, the bracing member 7' is cut out along the cutting lines 12. Therefore, it is possible to cut out a connection uniformly and carry out bracing work accurately.