To provide metal fittings and a method for jointing a cable rack which ensure excellent electrical conduction, enhance a fastening force of reinforcing metal fittings and acquire extremely high coupling strength when the reinforcing metal fittings are used.

Coupling metal fittings 10 are provided for abutting on outer side faces at ends of main beams P1 of the coupled cable rack P. The reinforcing metal fittings 20 are provided for abutting on inner side faces at the ends of the main beams P1. Cup square bolts 1 are provided for penetrating the reinforcing metal fittings 20, the main beams P1 and the coupling metal fittings 10. Coupling nuts 2 are disposed on the side of the coupling metal fittings 10. A peripheral edge P1b of a bolt insertion hole P1a punctured in the main beam P1 is pressed and deformed by a clamping plane of a cup square section 1A of the cup square bolt 1 in the direction of the coupling nut 2.