Store › 3" x 3" Galvanized Square Tube - 16 gauge - A500 Image 1 of 1 3" x 3" Galvanized Square Tube - 16 gauge - A500 from $6.00 OD 3” x 3" - ID 2-7/8” x 2-7/8” - Galvanized Square Tube - 16 gauge (1/16” wall thickness) - Grade A-500 Length: Select Length 12" 24" 36" 48" 60" 72" 84" 96" Quantity: Add To Cart Added! OD 3” x 3" - ID 2-7/8” x 2-7/8” - Galvanized Square Tube - 16 gauge (1/16” wall thickness) - Grade A-500