Stainless steel is a highly versatile material that is used for an endless amount of applications from machine parts to kitchen cutlery. You can use the materials to personalize or add branding to products by simply etching a word or symbol in the metal. Given the density of the material, it takes longer to etch into stainless steel than most other metal surfaces and the process must be performed carefully to avoid damage. There are multiple techniques for stainless steel etching with the most commonly used methods listed below:
The most common technique in stainless steel etching is chemical etching because it is easy, effective, and the required materials are inexpensive and are regularly available. There are different types of acids used in chemical etching which yield different results. The most effective acids have been mixed with water or vinegar. One popular type is ferric acid that has been diluted in water. Also, copper sulfate mixed with salt is commonly used with mild steel.
Another excellent choice is nitric acid with a ratio of 1:3 with water or vinegar. Sulfuric acid can also be used but is not preferred because it does not perform as well as the other options. However, if you choose this type of acid, ensure lower concentrations are used (between 10% and 25%) to get the desired result. Anything over 25% can burn too much into the metal and deliver sloppy-looking etched designs. Once the etching is complete, rinse the stainless steel thoroughly to remove all acid.
Also referred to as electrolytic etching, galvanic etching utilizes an electrolytic solution versus an acid. This process is like electroplating with the only difference between that the stainless steel is joined with the positive terminal of a 12-volt battery with the negative terminal being placed inside the electrolyte solution. Conversely, electroplating uses the negative terminal that is linked directly to the metal. This option is not as effective as chemical etching, but it still gives decent acceptable results.
As the name indicates, laser etching is a type of stainless-steel etching that utilizes lasers to etch directly into the material. It is not the best choice for a do-it-yourself project because it requires costly specialized equipment. However, it is the ideal choice for larger projects that require fast and accurate etching, such as those found in a manufacturing environment.
The method stainless steel etching method you select should be determined by the project type. Whichever is chosen, avoid pitting the metal, which can occur with long dwell times. For instance, if the metal is left in acid for too long, the surface can be destroyed, especially with a higher concentration of sulfuric acid. Etching stainless steel is not a difficult endeavor but ensure you are familiar with the technique to avoid mistakes.