Glossary · Trade
Burnishing
Polishing a metal surface, typically a pivot, by friction with a hard, smooth tool rather than an abrasive.
Explanation
Burnishing smooths and hardens a metal surface by rubbing it with a hard, polished tool rather than cutting it. In watchmaking it is the standard finish for pivots, done on a lathe or Jacot tool. A properly burnished pivot is bright, slightly work-hardened and runs longer than a merely polished one.
In the object catalogue
Catalogued objects whose own source record mentions “Burnishing”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
Tool
Watchmaker's jacot tool
“This object is a specialised watch- and clockmaker's jacot lathe used for burnishing pivots, held in the Science Museum Group collection under object number 1960-218. According …”
Tool
Safavid Brass Astrolabe Plate
“The metal surface shows slight mottling, patination, and circular machining or burnishing marks.”