Cost - Mild steel is the least expensive of all types of steel. Although it's not as strong as other steels, it's perfectly fine for moderately stressful applications such as home & garden items. Its low cost makes it extremely competitive for these low-strength everyday applications.
Ductility - Mild steel pipe is easy to bend, and doesn't break as quickly as its harder sibling, carbon steel tubing. Higher amounts of carbon cause brittleness, leading to an alloy that is more likely to snap than bend. Mild steel's ductility makes it perfect for tube bending, shaping, and welding.
Environmentally Friendly - Like other steels, mild steel can be reused and recycled many times over.
Lightweight - Carbon is heavy. Mild steel's low carbon percentage makes it easier to handle than carbon steel pipe.