Nail

In woodworking and construction, a nail is a pin-shaped, sharp object of hard metal or alloy used as a fastener. Historically made of wrought iron, today's nails are typically formed from steel, often dipped or coated to prevent corrosion in harsh conditions or improve adhesion. Ordinary nails for wood are usually of a soft, low-carbon or "mild" steel (about 0.1% carbon, the rest iron and perhaps a trace of silicon or manganese). Nails for concrete are harder, with 0.5-0.75% carbon.