Cutting Material: These bits feature tungsten carbide tips for clean, smooth, and accurate cutting in materials like stainless steel, mild steel, iron, cast iron, aluminum alloy, and even wood.Set Components: The kit typically includes 10 common metric sizes, such as 16mm, 18mm, 20mm, 22mm, 25mm, 30mm, 35mm, 45mm, 50mm, and 53mm.Design: Each hole saw is equipped with a titanium-plated pilot center drill and a spring to help with chip removal and precision.Storage: The set is contained within a foam-lined, silver-colored aluminum carrying case for protection and organization.