How to Make a Rough Metal Surface in Photoshop

In any Photoshop tutorial, things are always very subjective. So give yourself a chance to run though it once to decide for yourself what specific settings you would prefer. Anyway, let's get started; the first thing you need to do is pick the colors black and one other metallic color like a bluish-grey. Now go to Filter Menu/Render/Clouds, and the Apply Clouds filter.

Now, you should go to the Channels palette to make a new Channel. Then choose Filter Menu/Noise/Add Noise, and play with this until you get something you like. Now, still in the Channels palette, open the Image Menu/Adjustments/Levels and set the levels so the little triangles meet in the middle. Although, it sometimes works better if your triangles meet on the right side instead of the middle.

Because you used random noise, the graph will always look a bit different each time you do it. You can use Image/Adjustments/Curves to make slight adjustments. Next, go to Edit Menu/Transform and increase the scale some so that the dots are bigger. This blurs the dots a bit, which is what you want. Now, turn the dots into a selection by choosing the little icon at the bottom of the Channel palette that looks like a dotted circle.

Now go back to the Layers Palette. Choose the layer, copy the selection of dots, and then paste it. It will automatically be pasted into a new layer. Go to Layer Menu/Layer Style/Bevel and Emboss Bevel this new layer of dots. It works better if you pick Down for the direction, because it looks like little depressions instead of little raised bumps. By the way, don't pick white for the highlight for the beveling. Instead use a brighter tone of the primary color in your image. If you want a warmer feel, choose a light tan instead.

Next, pick a rust color that you think looks right. Select the paint brush tool. Go with a large size brush, setting the brush Mode to Color. Then reduce the brush's opacity to roughly 25% or so, and paint on your selected rust color. Now, use the lasso tool to make irregular shapes. Copy the shapes from the base metal color, and paste it to a new layer. Now add a very tiny bevel to these with the smallest of bevels, and again use white for highlights. Now create diagonal scratches and copy, paste, bevel those also. And there you have it!