Ultrapolished

Ultrapolished describes a surface finish achieving near-mirror smoothness and high reflectivity. It implies very low roughness and minimal scattering of light, typically achieved through multi-stage polishing and sometimes chemical or electrochemical finishing.

Common methods include mechanical polishing with progressively finer abrasives, buffing with microabrasive compounds, chemical polishing, electropolishing, and chemical-mechanical polishing. Electropolishing is notable for removing a thin layer to reveal a smoother, more corrosion-resistant surface.

Industries that use ultrapolished finishes include optics and photonics for lenses and housings; medical fields for implants and instruments; aerospace and automotive components; jewelry and watchmaking; kitchenware and consumer electronics casings; and architectural metal surfaces.

Characteristics and considerations: ultrapolished surfaces have low roughness (often sub-micron Ra) and high gloss but can be susceptible to visible fingerprints and smudges; they may require specialized cleaning; the term is sometimes used as marketing language rather than a standardized specification, with exact metrics varying by material and process.