The size of copper nails & stainless steel nail is 3.5in x 3.5mm, the drill bit nail size is 2.7in x3.5mm. Premium Materials: These hardware nails are mainly made of pure copper and stainless steel, which are sturdy and, rust proof and anti-, and have a long service life; The drill bit is made of cobalt containing high speed steel, which is to heat, wear and deformation.
