finish_polish_bead_blast

Bead-blast

polish · matte · glass-bead blast, soft satin, matte blast

Pelt the surface with tiny glass beads under air pressure. The peen-pattern leaves a uniform, soft, non-directional matte — Apple's silver-aluminum laptops, the body of a Leica camera, the back of a stainless watch case. Reads as deliberate, neutral, modern.

Compressed-air abrasive blasting with spherical glass-bead media (#10–#16 mesh typical for fine work, #4–#8 for coarser texture). The bead is non-fracturing, so it peens rather than cuts — finish is a uniform matte with mild compressive residual stress. Ra typically 0.8–1.6 µm depending on bead size and pressure. Common pre-treatment under anodizing (the matte takes dye uniformly) and PVD coating.

character — isotropic matte, soft, even, neutral, fingerprint-tolerant.

Finish properties

  • levelmatte
  • subcategorymedia abrasion
  • Ra (µm)1.2
  • applies tometal

Second life

reversibilitymoderate — a polished surface can be re-roughened (sandblast, brush, etch) and a roughened surface can be re-polished; the substrate is preserved unless polishing-induced material loss is significant.
blocks substrate recyclingno
renewabilityvery high — polishing is the canonical maintenance operation for almost any hard surface; field-renewability is high for accessible surfaces, shop-renewability for everything else.

ASM Handbook Vol. 5 Surface Engineering; manufacturer abrasives literature (3M, Norton, Mirka).

Citations