Store › 3" Round Tube - Mild steel - ERW - 16 gauge Image 1 of 1 3" Round Tube - Mild steel - ERW - 16 gauge from $15.50 OD 3” - ID 2-7/8” - Round Metal Tube - 16 gauge (1/16” wall thickness) - ERW - ASTM A513 - Mild Steel - Cold Rolled Length: Select Length 12" 24" 36" 48" 60" 72" 84" 96" Quantity: Add To Cart Added! OD 3” - ID 2-7/8” - Round Metal Tube - 16 gauge (1/16” wall thickness) - ERW - ASTM A513 - Mild Steel - Cold Rolled