Sizes Most countries, except the United States, use a metric system for describing nail sizes. A 50 × 3.0 indicates a nail 50 mm long (not including the head) and 3 mm in diameter. Lengths are rounded to the nearest millimetre.
sizes most countries except the united states use a metric system for describing nail sizes a 50 × 30 indicates a nail 50 mm long (not including the head) and 3 mm in diameter lengths are rounded to the nearest millimetre