Surface Finishing

Surface finishing covers mechanical processes such as polishing, buffing, bead blasting, sand blasting, brushing and vibratory deburring that achieve a specified appearance or roughness (Ra). They are used on their own or to prepare parts before plating, anodizing or coating.

What it is

Each process changes the surface in a different way: polishing and buffing produce a smooth, reflective finish; bead blasting gives a uniform satin-matte look; sand or grit blasting cleans and roughens for coating adhesion; brushing gives a directional satin grain; vibratory and barrel finishing deburr and smooth many small parts at once.

The target is usually stated as a roughness value (Ra in µm) or as a visual standard or sample. Choosing the finish before plating or anodizing matters, because those coatings reproduce the surface underneath.

Points to consider

• State the finish as an Ra value or provide a reference sample to avoid mismatched expectations.
• Blasting can slightly change dimensions and edge sharpness; mask critical surfaces.
• Finish direction (brushed grain) should be shown on the drawing where it matters.
• Polishing before plating gives a bright plated finish; blasting before anodizing hides tool marks.

Frequently asked questions