Easy Textures - Brushed Metal 1

Start with a new image, Background Color: White, 16 Million Colors.

Step 1:
Image - Special Filters - Add Noise.
Select Random and 100% Noise.

Step 2:
Colors - Grey Scale.
Colors - Increase Color Depth - 16 Million Colors.

Step 3:
Image - Deformations - Motion Blur.
Set Direction = 90 Degrees and Intensity = 40 Pixels.

If you want a sharper structure, just use Sharpen or Sharpen More.

Here´s a variation where Motion Blur was set to 135 Degrees instead of 90.