Creating textured or distressed metal surfaces is a popular technique in industrial design, automotive customization, and home decor to achieve a rugged, vintage, or artistic look. Here are the most common methods used:

1. Sandblasting: This abrasive technique uses high-pressure air to blast sand or other media onto the metal, creating a rough, matte texture ideal for industrial finishes.

2. Acid Etching: Chemical solutions like ferric chloride or nitric acid are applied to corrode the metal surface selectively, producing intricate patterns or an aged appearance.

3. Hammering: Manual or pneumatic hammers create dents and irregularities, giving the metal a handcrafted, artisanal texture.

4. Wire Brushing: A wire brush or wheel scrapes the metal surface, leaving fine scratches that mimic natural wear and tear.

5. Heat Distressing: Controlled heating and rapid cooling (quenching) can warp and oxidize the metal, resulting in a cracked or burnt effect.

6. Rusting Techniques: Accelerated rusting using saltwater, vinegar, or hydrogen peroxide creates an authentic weathered look without long-term exposure.

7. Grinding and Stamping: Mechanical grinding or stamping adds deep grooves or embossed designs for a heavily distressed aesthetic.

Each method offers unique results, allowing designers and craftsmen to tailor textures for specific projects, from steampunk furniture to vintage car parts. Experimenting with combinations of these techniques can yield even more striking effects.