4% Nital

General Purpose

Composition

4% Nitric Acid in Ethanol

Method

Immersion

Time

12s

Alternative Names

Grain boundaries, ferrite, pearlite, bainite

Intermediate concentration between 3% and 5% Nital. Good balance for medium-hardness steels.

Pearlite darkens, ferrite remains light

Method:immersion

Typical Time:12 seconds

Mix 4 ml concentrated nitric acid (HNO₃) with 96 ml ethanol. Add acid to ethanol slowly with stirring.

Immerse sample for 12-25 seconds. Intermediate aggressiveness between 3% and 5% Nital. Rinse with ethanol then water.

Good intermediate option when 3% is too light and 5% is too aggressive. Adjust time based on material response.

Store in dark glass bottle. Shelf life: 3-6 months.