Pack of 100 steel picture nails dimensions: 2.0 x 16 mm, material: steel white blued, steel nail HKB 100 pieces steel picture nails Blaukopf lens head dimensions: 2.0 x 16 mm, head approx. 3.5 mm, material: iron hardened, blued, hardened steel nails are ideal for use in hard materials such as stone, concrete or hardwood. Due to the high hardness of the substrate, they only need a small penetration depth to form a firm connection. The harder the material, the shorter the nail should be. Our nails are manufactured in state-of-the-art hardening systems only from the point of view of optimal hardness, so that the colour of the nails can vary from blue to brown to black. Do not pay attention to the colour of the nail, but how it works. Better to take quality nails features hardened, lens head, blank place of application nail in stone, concrete or wood