| Adler Etchant | HCl, Copper ammonium chloride, FeCl3, water | 60-75%, 20-30%, 10-20%, 2-5% | Immersion | 300 series stainless steel, superalloys |
| Al-NaOH Etchant | Water, NaOH | 85-95%, 5-15% | Immersion | Aluminum alloys |
| Ammonium Persulfate Etchant | Water, (NH4)2S2O8 | 28-79%, 15-25% | Immersion | Copper and brass alloys |
| ASTM No. 30 | NH4OH, water, H2O2 | 21-72%, 28-79%, 1-4% | Swab 5-45 sec | Copper and copper alloys; mix fresh (H₂O₂ degrades quickly) |
| ASTM 97 | Water, KOH | 50-60%, 40-50% | Electrolytic, 2.5V | Fe-Cr-Ni alloys |
| ASTM No. 157 | HCl, water, CrO3 | 40-70%, 25-50%, 10-25% | Immersion | Hastelloy |
| Beraha's | Water, Na2S2O3, K2S2O5 | 85-95%, 5-15%, 2-5% | Immersion | Tool steel - colors ferrite, martensite, etc. |
| Carpenter's | Ethanol, HCl, HNO3, FeCl3, methanol, IPA, CuCl2 | 35-55%, 35-55%, 2-5%, 1-5%, 0-5%, 0-2%, 0.5-1.5% | Immersion, 20°C | Duplex and 300 stainless steels |
| Copper No.1 | Water, HNO3 | 65-70%, 30-35% | Immersion, 20°C | Copper and brass |
| Copper No.2 | Water, HCl, FeCl3 | 67-85%, 10-15%, 5-10% | Immersion, 20°C | Copper and brass |
| CU-PASS-SOL | CuSO4·5H2O, H2SO4, DI Water | 40g, 1.5ml, 245ml | Swab application | Detects free iron on stainless steels |
| Dichromate | Water, H2SO4, NaCl, K2Cr2O7 | 80-90%, 5-10%, 2-10%, 2-5% | Immersion, seconds to minutes | For Cu-Sn (tin bronze) |
| Fry's Etchant | Ethanol, HCl, water, methanol, IPA, CuCl2 | 55-70%, 30-50%, 5-15%, 1-5%, 1-5%, 0.4-2% | Immersion, 20°C | Martensitic and PH stainless steels |
| Inconel Etchant | HCl, water, HNO3, H2O2 | 20-40%, 10-50%, 10-30%, 10-20% | Use fresh only | Macro etch for Ni alloys |
| Kalling's No. 2 | CuCl2, HCl, Ethanol | 5g, 100ml, 100ml | Immersion/Swab, 20°C | Duplex, Ni-Cu superalloys |
| Keller's | Water, HNO3, HCl, HF | 90-95%, 5-10%, 5-10%, 1-5% | 10-30 sec immersion | Aluminum and titanium |
| Klemm's Reagent | Water, Na2S2O3, K2S2O5 | 70-85%, 25-50%, 5-10% | Seconds to minutes | Brass, bronze, cast iron, steel; shares SDS with Klemm's 2 |
| Klemm's 2 | Water, Na2S2O3, K2S2O5 | 70-85%, 25-50%, 5-10% | Up to minutes at 40°C | Copper, cast iron, tin; shares SDS with Klemm's Reagent |
| Kroll's | Water, HNO3, HF | 90-95%, 4-8%, 1-5% | Swab up to 20 sec | Titanium and alloys |
| Marble's | Water, HCl, CuSO4 | 70-85%, 10-20%, 2-10% | Swab or immerse 5-60 sec | Ni, Ni-Cu, Ni-Fe superalloys |
| Murakami's | K3Fe(CN)6, KOH, Water | 10g, 10g, 100ml | Mix KOH + Water first | Carbides, Cr, Mo, WC-Co alloys |
| Nickel Etchant | Water, HNO3, H2SO4, NaCl | 50-70%, 20-40%, 2-10%, 2-10% | Immersion | Macro etch for nickel and Ni-base alloys |
| Nital | Ethanol, HNO3, methanol, IPA | 85-98%, 1-8%, 1-5%, 1-5% | Seconds to minutes | Common Fe, steel etchant; HNO3 % varies by SKU (NITAL-2 through NITAL-8) |
| Oberhoffer's Reagent | Ethanol, Water, HCl, FeCl3, SnCl2 | 40-48%, 40-48%, 2-5%, 2-4%, 0.01-0.1% | Immersion | Phosphorus segregation in low-carbon steels and cast irons |
| Picral | Ethanol, picric acid, methanol, IPA, water | 80-90%, 8-12%, 0.5-5%, 0.5-5%, 0.5-1.5% | Seconds to minutes | Ferrite, carbide, bainite, etc. |
| Titanium Attack Polish (TI-AP-16) | Water, amorphous silica, NH4OH, H2O2 | 40-60%, 30-50%, 7-12%, 0.1-1% | Final polishing on napped pad | Chemomechanical attack polish for titanium alloys (colloidal silica base) |
| Vilella's | Ethanol, HCl, picric acid, methanol, IPA, water | 80-90%, 2-5%, 0.5-1.5%, 0.5-5%, 0.5-5%, 0.5-1.5% | Seconds to minutes | Ferrite-carbide in steels; contains picric acid |
| Waterless Kalling's | HCl, ethanol, CuCl2, methanol, IPA | 40-55%, 40-55%, 0.5-10%, 0.5-2%, 0.5-2% | Immersion or swab | Iron-base and nickel-base superalloys; concentrated HCl-in-denatured-ethanol (no water) for moisture-sensitive samples |
| Weck's | Water, ammonium bifluoride, HCl | >85%, 10%, 0.04-0.4% | Seconds to minutes | Tint etch for Ti alloys |
| Winsteard's Reagent | Ethanol, HCl, picric acid, methanol, IPA, sodium tridecylbenzene sulfonate, water | 80-90%, 2-5%, 0.5-1.5%, 0.5-5%, 0.5-5%, 4-5%, 0.5-1.5% | Immersion or swab | Macro etch for chromium and stainless steels; contains picric acid |
