ForMatter/Finishes/polish/Burnished (hand-tool polish)
finish_polish_burnished

Burnished (hand-tool polish)

polish · polished · agate burnish, steel burnish, hand burnishing, rubbing-stone polish

A high-shine produced not by removing material but by deforming the surface — a hard polished tool (agate stone, polished steel rod, hematite, bone) rubbed against soft metal compacts the high points into the low ones. The bright surface on water-gilded leaf, the polished bezel on a hand-set silver bowl, ancient burnished black-pottery (Greek terra sigillata).

Cold plastic deformation polishing — a tool harder than the workpiece, with a smooth polished face, rubbed under controlled pressure across the surface. No abrasive, no material removal: the asperities flow downward into the valleys. Surface roughness drops by an order of magnitude (Ra 0.4 → 0.04 µm typical). Cold-work hardens the surface (~10–20% Vickers increase on silver / gold). Burnishing tools: agate stones (water-gilding standard since the medieval period), polished hematite, polished steel rods (modern jewelry workshop), wood tools (terra sigillata burnishing in pottery). Distinct from compound polish — compound polish abrades; burnishing compacts.

character — high specular shine without material removal, work-hardened surface, traditional craft register.

Finish properties

  • levelpolished
  • subcategorynon-cutting compaction polish
  • Ra (µm)0.04
  • applies tometal, ceramic

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