Industrial Etching - Common Etchants

Common Etchants

For aluminium

• sodium hydroxide
• Keller's reagent

For steels

• hydrochloric and nitric acids
• ferric chloride for stainless steels
• Nital (a mixture of nitric acid and ethanol, methanol, or methylated spirits for mild steels.

2% Nital is common etchant for plain carbon steels.

For copper

• cupric chloride
• ferric chloride
• ammonium persulfate
• ammonia
• 25-50% nitric acid.
• hydrochloric acid and hydrogen peroxide

For silica

• hydrofluoric acid (HF) is a very efficient etchant for silicon dioxide. It is however very dangerous if it comes into contact with the body.