Create a 3D model of a metallic screw head based on the reference image. The broken area at the top should be fully repaired and symmetrical, as if new. The surface should be smooth, polished, and reflective like chrome. The edges should retain the same wavy or gear-like outer shape. Add realistic screw threading (spiral grooves) along the central shaft to make it look like a functional screw. Render the model in high detail, with accurate lighting and metallic reflections, isolated on a black background.