The following information is supplied for technical support only.
MetPrep DO NOT supply etchants in any form.

MetPrep Ltd are delighted to be able to publish a range of standard etchants.

Our intention is to offer a more comprehensive range of preparation parameters that will enable you to improve your own preparation techniques.

We will also attempt to include any etchants that you would be happy to recommend. Please send the details to Metprep Ltd.

Where water is advised please note that this refers to distilled water in all cases.

Carbon Steels

Macro Etchspacer_10px10% Nital
10ml Nitric Acid
90ml Methanol
spacer_10pxVersatile macro etch for Iron & Steel. Carburized and Decarburized areas as well as segregation.
Micro EtchNital - 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 EtchPicral
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 EtchVilella's Reagent
1g Picric Acid
5ml HCl
100ml Ethanol
General structure of low alloy steels. Reveals prior austenite grain boundaries and bainitic structures.

Stainless Steels

Macro Etchspacer_10pxMarble's Reagent
50ml HCl
25ml Saturated
aequous solution of Copper(II) Sulphate
spacer_10pxUsed for revealing general structure.
Micro EtchAcid Ferric Chloride
10 g Ferric Chloride
30 ml HCl
120 ml Water
Swab etch to reveal general microstructure.
Micro EtchKallings 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 Etch45ml Glycerol
15ml Nitric Acid
30ml Hydrochloric Acid
For stainless steels with high Cr content. Also Cr-Ni Cast steels.

Tool Steels

Micro Etchspacer_10pxSodium Picrate
1g Sodium Picrate
100ml Water - use boiling
spacer_10pxIron Tungstide is quickly darkened, Iron-Tungsten Carbide is slowly darkened and cementite is unaffected.
Micro EtchMethanol Regia
5 ml Nitric Acid
10 ml HCl
100ml Methanol
General microstructure.

Titanium Alloys

Macro Etchspacer_10px50ml HCl (1.19)
50ml Water
spacer_10pxFor differentiation of alpha and beta Titanium.
Macro Etch30ml HCl (1.19)
10ml HF
10ml Nitric Acid
50ml Water
General purpose macro etch for all Titanium alloys.
Micro EtchKroll's Reagent
2ml HF
10ml Nitric Acid
88ml Water
Useful etchant for most Ti based materials, especially Ti-Al-V alloys.
Micro Etch15ml 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.

Copper Alloys

Macro Etchspacer_10px50ml Nitric Acid (1.40)
50ml Water
spacer_10pxMacro etch for most Copper and Brasses. For grains and cracks.
Micro Etch5g Iron (III) Nitrate
25ml HCl
70ml Water
General purpose etchant that reveals grain boundaries. Use by immersion.

Aluminium Alloys

Macro Etchspacer_10pxMixed Acids
5ml HF
20ml Nitric Acid
20ml HCl
60ml Water
spacer_10pxUseful macro etch for most Al based materials. Reveals grain size, rolling directions and welded joints. - De-smut in 35% Nitric Acid afterwards.
Micro EtchKeller'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.

Nickel Alloys

 Macro Etchspacer_10px10g Copper Sulphate
50ml HCl
50ml Ethanol
50ml Water
spacer_10pxVersatile macro etch for Nickel & Nickel based Alloys. May reveal grain structure in Superalloys.
 Micro EtchKalling'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.

 Magnesium Alloys

Macro Etchspacer_10pxMixed Acids
5ml HF
20ml Nitric Acid
20ml HCl
60ml Water
spacer_10pxUseful macro etch for most Mg based materials.
Micro EtchAcetic 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 EtchCitric Acid
10g Citric Acid
90 ml Water
General structure.
Micro EtchAcetic Picral
2ml Nitric Acid
98ml Methanol
General structure, particularly good for Zr containing alloys.

Molybdemum & Tungsten

Micro Etchspacer_10px36g Sodium Hydroxide
36g Potassium Ferricyanide
100ml Water
spacer_10pxImmersion etch for 10secs.

Niobium/ Tantalum Alloys

Micro Etchspacer_10px5ml HF
95ml Nitric Acid
spacer_10pxUseful etch for Niobium.
Micro Etch60 ml HF
20ml Nitric Acid
20ml Glycerol
General structure for Niobium.
 Micro Etch50ml HF
10g Ammounium Fluoride
For Tantalum. A much shorted etching time is required when the reagent is hot.

Shopping Basket
Scroll to Top