I came across bart's collection of metal textures/photos (http://opengameart.org/content/45-high-res-metal-and-rust-texture-photos) and thought I'd take out some of the grates and create completed, ready to use textures out of them.

Included in this pack are three different metal grates: a rusted vent grille and two sewer drain grates.

All are 512x512, PNG format. Normal maps included.