Abstract: A composite coating is provided for a tool. The tool can be a pair of scissors or a screwdriver for example. The tool is made with at least one contact face. The composite coating includes diamond grains and layer of metal oxide. The metal oxide is used as an adhesive to secure the diamond grains to the contact face.

Abstract: A diamond membrane includes a substrate having a substrate surface and defining a normal line perpendicular to the substrate surface, a first bonding layer formed on the substrate surface of the substrate with the major axes of the bonding crystals thereof extending at an angle within 0˜45-degrees relative to the normal line, diamond grains evenly distributed over the exposed outer surface of the first bonding layer to force gaps among the bonding crystals of the first bonding layer sideways for enabling the diamond grains to be partially engaged into the first bonding layer and partially protruding over the exposed outer surface of the first bonding layer, and a second bonding layer formed on the surface of the first bonding layer and the periphery of the diamond grains with the major axes of the bonding crystals thereof extending at an angle within 45˜90-degrees to let the diamond grains partially protrude over the second bonding layer.