ASTM No. 1

general purpose

Composition

100ml Ethanol, 1-5ml HNO₃

1-5%

Method

immersion

Time

10s

Basic Information

Category:General Purpose

Composition:100ml Ethanol, 1-5ml HNO₃

Concentration:1-5%

Reveals:Grain boundaries, ferrite, pearlite

Typical Results:ASTM standard general-purpose etchant. Similar to Nital but with variable concentration. Good for carbon and low-alloy steels.

Color Effects:Pearlite darkens, ferrite remains light