4.5 in. H X 1.5 in. W X 0.125 in. D Black Carbon Steel Flat Corner Plate, National Hardware, Mfr#: N351-504$4.79+
150 in H X 1025 in W X 14 in D Black Steel InsideOutside Corner Brace, Hampton, Mfr#: 02-3405-025$13.59+
Hampton 3-1/2 in. H X 1-1/2 in. W X 3/16 in. D Black Steel Offset Leg Corner Brace, Hampton Products, Mfr#: 01-3405-307$3.65+
Hampton 1-5/8 in. H X 3 in. W X 1/8 in. D Black Steel Wide Corner Brace, Hampton Products, Mfr#: 01-3405-401$2.83+
Z Purlin Angled Flange Clip: 1/16in.-1/4in. Purlin/Beam/Flange, 100PK, Winnie Industries, Mfr#: WAF14$100.99+
3-1/2 in. H X 3/4 in. W X 3-1/2 in. D Black Steel Inside L Corner Brace, Hampton, Mfr#: 01-3404-267$2.29+