Set of 100 pieces of nails for a nail gun 25mm. Set of 100 pieces of nails for a nail gun 25mm. These nails are ideal for various types of surfaces, including concrete, bricks, wood, metal, and other materials. For softer materials like wood, ensure that their thickness is at least 3-4 mm. For metal surfaces, aim for a thickness of less than 3-5 mm for better results.