HN03. An inorganic, highly irritant, transparent acid. Spec. weight 1.522; boiling point 84°C. Extracted from Chile saltpetre, nitrogen or ammonia. Except for gold and platinum, nitric acid attacks nearly all metals quickly and forms so-called nitrates with them. Use: Degreasing and light etching of metal parts (approx. 5%), so that with wood/metal putties the putty or glue has good adhesion.