Be specific and reference industry standards:
- As-Extruded (Mill Finish): Specify “As extruded” or “Mill finish.” Note that it may have visible die lines and slight variations.
- Anodizing: Specify type and thickness. E.g., “Clear anodize, AA-M12C22A41 per MIL-A-8625” (Type II, Class 1, 0.4 mil thickness). Or “Black anodize, 20-25μm thickness.”
- Powder Coating: Specify color (using RAL or Pantone codes), gloss level (e.g., semi-gloss), and thickness. E.g., “Powder coat RAL 7016, 60-80μm.”
- Mechanical Finishes: Specify “Satin brush finish,” “Polished to #600 grit,” or “Glass bead blasted.”
Include requirements for surface imperfections (e.g., “No visible scratches or pits on show surfaces”) and consider providing a physical sample as a reference.