2% Nital

General Purpose

Composition

2% Nitric Acid in Ethanol

Method

Immersion

Time

Alternative Names

Grain boundaries, ferrite, pearlite

Reveals ferrite grain boundaries and pearlite colonies. Darkens pearlite, leaves ferrite light.

Pearlite darkens, ferrite remains light

Method:immersion

Typical Time:5 seconds

Mix 2 ml concentrated nitric acid (HNO₃) with 98 ml ethanol (95% or absolute). Add acid to ethanol slowly with stirring. Store in glass bottle.

Immerse sample for 5-15 seconds. Swab gently if needed. Rinse immediately with ethanol, then water. Dry with compressed air.

If over-etched (too dark), reduce time or concentration. If under-etched, increase time slightly. Ensure fresh etchant for best results.

Store in dark glass bottle with tight cap. Keep away from light. Shelf life: 3-6 months if properly stored.