Macro Etch

10% Nital
10ml Nitric Acid
90ml Methanol

Versatile macro etch for Iron & Steel. Carburized and Decarburized areas as well as segregation.

Micro Etch

Nital
1-10ml Nitric Acid
90-99ml Methanol

Most common etchant for Iron, Carbon and Alloy Steels & Cast Irons. Reveals alpha grain boundaries and constituents. The 2% solution is the most common. Use by immersion for up to 60 seconds or by swabbing. The 5-10% solution is used for high-alloy steels.

Micro Etch

Picral
2-4g Picric Acid
100ml Ethanol

Generally used for Iron and heat treated Steels. Recommended for pearlite, marteniste and bainite structures. Use by immersion or swabbing.

Micro Etch

Vilella's Reagent
1g Picric Acid
5ml HCl
100ml Ethanol

General structure of low alloy steels. Reveals prior austenite grain boundaries and bainitic structures.

Macro Etch

Marble's Reagent
50ml HCl
25ml Saturated
aequous solution of
Copper(II) Sulphate

Micro Etch

Micro Etch

Kallings Solution
2 g Cupric Chloride
40-80ml Methanol
40ml Water
40ml Hydrochloric Acid

Ferrite and Martensite are darkened. Austenite appears light and carbides are unaffected.

Micro Etch

45ml Glycerol
15ml Nitric Acid
30ml Hydrochloric Acid

For stainless steels with high Cr content. Also Cr-Ni Cast steels.

Micro Etch

Sodium Picrate
1g Sodium Picrate
100ml Water
use boiling

Iron Tungstide is quickly darkened, Iron-Tungsten Carbide is slowly darkened and cementite is unaffected.

Micro Etch

Methanol Regia
5 ml Nitric Acid
10 ml HCl
100ml Methanol

Macro Etch

50ml HCl (1.19)
50ml Water

For differentiation of alpha and beta Titanium.

Macro Etch

30ml HCl (1.19)
10ml HF
10ml Nitric Acid
50ml Water

General purpose macro etch for all Titanium alloys.

Micro Etch

Kroll's Reagent
2ml HF
10ml Nitric Acid
88ml Water

Useful etchant for most Ti based materials, especially Ti-Al-V alloys.

Micro Etch

15ml Hydrogen Peroxide
10ml Aqueous solution
of Potassium Hydroxide
80ml Water

Swab etch for Titanium, Ferro-Ti, Ti-Al-V-Sn alloys. Alpha Ti is attacked, beta Ti is left unchanged.

Macro Etch

50ml Nitric Acid (1.40)
50ml Water

Macro etch for most Copper and Brasses. For grains and cracks.

Micro Etch

5g Iron (III) Nitrate
25ml HCl
70ml Water

General purpose etchant that reveals grain boundaries. Use by immersion.

Macro Etch

Mixed Acids
5ml HF
20ml Nitric Acid
20ml HCl
60ml Water

Useful macro etch for most Al based materials. Reveals grain size, rolling directions and welded joints.
De-smut in 35% Nitric Acid afterwards.

Micro Etch

Keller's Reagent
2.5 ml Nitric Acid
1.5 ml HCl
1 ml HF
95 ml Water

Most common etchant for Al & Al Alloys, except high Si alloys. Swab etch 10 - 20 seconds.

Macro Etch

10g Copper Sulphate
50ml HCl
50ml Ethanol
50ml Water

Versatile macro etch for Nickel & Nickel based Alloys. May reveal grain structure in Superalloys.

Micro Etch

Kalling's
2g Copper Chloride
40ml HCl
40-80ml Ethanol

Useful etchant for superalloys and stainles steels as well as Ni-Cu alloys. Good for grain structure. Generally used as swab etch.

Macro Etch

Mixed Acids
5ml HF
20ml Nitric Acid
20ml HCl
60ml Water

Useful macro etch for most Mg based materials.

Micro Etch

Acetic Picral
100g Picric Acid
200ml Methanol
800ml Acetic Acid
800 ml Water

For general structure, reveals grain boundaries and twins.
This solution must be allowed to age for 24 hours

Micro Etch

Citric Acid
10g Citric Acid
90 ml Water

General structure.

Micro Etch

Acetic Picral
2ml Nitric Acid
98ml Methanol

General structure, particularly good for Zr containing alloys.

Micro Etch

36g Sodium Hydroxide
36g Potassium Ferricyanide
100ml Water

Immersion etch for 10secs

Micro Etch

5ml HF
95ml Nitric Acid

Useful etch for Niobium.

Micro Etch

60 ml HF
20ml Nitric Acid
20ml Glycerol

General structure for Niobium.

Micro Etch

50ml HF
10g Ammounium Fluoride

For Tantalum. A much shorted etching time is required when the reagent is hot.