Common Etchants

OMMON ETCHANTS CAUTION:Safety is very important when etching. Be sure to wear the appropriate protective clothing and CAUTION:Safety observe all WARNINGS WARNINGS on  on chemical manufacuters MSDS. Also review the COMM!"S and CO!D#"#O!S Section for each etchant.

Recommended Etchants  Aluminum alloys

 High carbon steel 

 Brasses and Bronzes

Stainless steel 

Cast Iron

Tin alloys

Copper alloys

 Zinc alloys

Weld or Low carbon steel 

Ceramics

 Hastelloy and ic!el  Superalloys

The following table lists the most commonl !sed etchants

Etchant

 AS"M !o.

%$ Adler tchant

Com"osition

Conc#

Conditions

Comments

 Ammonia &ydrogen 'ero(ide )$*+ D# ,ater 

-./ ml 0/ ml -./ ml

Mi( Ammonia and water before adding pero(ide. Must be used fresh. Swab /12/ seconds

3or etching copper4 copper alloys and copper1silver alloys.

Copper ammonium chloride &ydrochloric acid 3erric chloride4

5 grams 0/% ml 2/ grams 6/ ml

#mmersion is recommended for 

3or etching $%% series stainless steel and

hydrated D# ,ater 

several seconds

&astelloy superalloys

Carpenters Stainless Steel tch

3eCl$ CuCl &ydrochloric acid !itric acid thanol

7./ grams .2 grams 0 ml - ml 0 ml

#mmersion etching at % degrees Celsius

3or etching duple( and $%% series stainless steels.

8alling9s !o. 

CuCl &ydrochloric acid thanol

/ grams 0%% ml 0%% ml

#mmersion or swabbing etch at % degrees Celsius

3or etching duple( and 2%% series stainless steels and !i1Cu alloys and superalloys.

8ellers tch

Distilled water  !itric acid &ydrochloric acid &ydrofluoric acid

05% ml / ml $ ml  ml

0%1$% second immersion. se only fresh etchant

(cellent for aluminum and titanium alloys.

8lemm9s ;eagent

Sodium thiosulfate solution 'otassium metabisulfite

/% ml Saturated / grams

tch for a few seconds to minutes

3or etching alpha1beta brass4 bon
8roll=s ;eagent

Distilled water  !itric acid &ydrofluoric acid

5 ml - ml  ml

Swab specimen up to % seconds

!ital

thanol !itric acid

0%% ml 010% ml

#mmersion up to a few minutes.

(cellent for titanium and alloys.

Most common etchant for 3e4 carbon and alloys steels and cast iron 1 #mmerse sample up from seconds to minutes> Mn1 3e4 Mn!i4 Mn1Cu4 Mn1 Co alloys.

Marble9s ;eagent

Mura?ami9s

CuSO2 &ydrochloric acid ,ater 

8$3e)C!+8O& ,ater 

0% grams /% ml /% ml

0% grams 0% grams 0%% ml

#mmerse or swab for  /1-% seconds.

3or etching !i4 !i1Cu and !i13e alloys and superalloys. Add a few drops of &SO2 to increase activity.

're1mi( 8O& and water before adding 8$3e)C!+-

Cr and alloys )use fresh and immerse+> iron and steels reveals carbides> Mo and alloys uses fresh and immerse> !i1Cu alloys for alpha phases use at 6/ Celcius> , and alloys use fresh and immerse> ,C1Co and comple( sintered carbides.

;ecommended for microstructures containing ferrite4 carbide4 pearlite4 martensite and bainite.  Also useful for magnetic alloys4 cast iron4 high alloy stainless steels and magnesium.

ood for ferrite1carbide structures )tempered martensite+ in iron and steel

'icral

thanol 'icric acid

0%% ml 12 grams

Seconds to minutes Do not let etchant crystalli
ilella=s ;eagent

'icric Acid &ydrochloric acid thanol

0 gram / ml 0%% ml

Seconds to minutes