Risks of Electropolishing

We get questions all the time about what the risks of electropolishing are. Here are a few:

Electropolishing Material Loss

If you have a small medical product which has extremely tight tolerances, you run the risk of losing some material and becoming out of spec. Electropolishing requires connection to an electricity emitting cable. From time to time, this connection can leave a mark on products. It is very important if you have a small tolerance product to identify where the connection should be made to your product.

Electropolishing Handling

As with any manufactured product, there is going to be handling on the manufacturing floor and often shipping and receiving. The risks of electropolishing also include proper washing, rinsing and passivation before the process.

Material Composition Change

Many of our customers ask us if the electropolished product has different characteristics than the original product. The answer is that the material has changed, very slightly but there aren’t any new risky characteristics about your products external material composition. Since the material change is minimal you should be able to use electropolished stainless steel in any procedure that you would use non-electropolished stainless steel.

These are just a few risks of electropolishing. Over time we have done everything we can to alleviate potential risks associated with this process. Just ask any of our satisfied customers!


New Equipment

Classic Electropolishing is considering a new Wash, Rinse and Citric Passivation system. We are looking at Ramco equipment. Does anyone have any other suggestions for optimal wash and rinse systems? Our main goal is quality. Secondarily automation.

How Do I Wash My Equipment after Electropolishing and Passivation?

We recently had someone from the food industry reach out with a question and we thought we would share the answer on our blog because I’m sure other people have had the same question in the past. The question was “If I were to passivate and electropolish my food processing equipment, what would be the proper way to clean and maintain them?”

There is no difference to washing your equipment after electropolishing. If you have a process for washing your stainless steel equipment, normally which is dictated by your industry, there will be no difference after the electropolish. Electropolishing will make your equipment more corrosion resistant which should make your equipment last longer but it won’t change how you wash your equipment.

Sorry for the anti-climactic post, we just figured other people might have the same question and we wanted to give them the answer before they had to reach out. If you have questions of your own don’t hesitate to reach out.

ASTM A380 & Citric Acid Passivation

ASTM A380 is the “Standard Practice for Cleaning, Descaling, and Passivation of Stainless Steel Parts, Equipment, and Systems”

For many industries, including military and medical specifications, the ASTM A380 standard provides the recipe for good passivation process and testing to ensure the successful passivation of a product or equipment. We wanted to verify that this standard included citric passivation and not only nitric passivation. ASTM A380 does not explicitly mention citric acid passivation. However, citric acid passivation is mentioned in ASTM A967 and does meet the requirements as referenced in ASTM A967.

Others ways that this ASTM is written out include ASTM A-380 and ASTM A 380. For more information on ASTM A380, please visit the ASTM website:

If you are planning to undertake passivation make sure to have the proper process in place such that you adhere to ASTM standards. For instance, passivation typically require a pre-process step and a post-process step. Also make sure that you have stringent process as it relates to the solution testing and use policy.

If you need citric acid passivation services based on ASTM A380, please contact us today, we can help!

Medical Device Electropolishing – Finishing Requirements

At Classic Electropolishing, we get a lot of medical device electropolishing requests. So many so that I decided it would be worthwhile to research finishing requirements for medical device products to see if it was actually an FDA requirement. I found that while it is not a “required” finish, many medical device designers using stainless steel 300 level wire choose to get their product passivated and/or electropolished.

This process gives the stainless steel a brighter finish. The finish exudes a look of quality which can command a higher price. The passivation and electropolishing process also helps to remove burrs that were created in the machining process leading to tighter tolerances and more refined products.

After the medical device finishing, medical device designers decide whether they will be responsible for the sterilization or whether there product can be sterilized on site by the medical provider.

Hopefully this blog article was helpful for medical device designers looking into medical device electropolishing, please contact us for help with your next electropolishing project!


Food Equipment Passivation

FDA food industry recalls happen for a variety of reasons. It is difficult to foresee every potential problem but it is possible to take protective measures against chemicals harboring themselves inside of empty space in your stainless steel. One such protection against  is food equipment passivation. Passivating your food equipment will help protect against corrosion and help provide a longer “shelf life” for your food equipment.

After your stainless steel food equipment is put to use, it can begin to wear down. This can happen by an abrasive process such as grinding or brushing your equipment. It can also happen due to chemical reactions, the chemicals in your food reacting with the stainless steel. Over time these processes wear at the “passive” layer of stainless steel. The process of passivation helps to secure this layer for uniformity and corrosion resistance.

– 3A Standards also provide specifications regarding alloys and other coatings used in fabrication. The properties of stainless steel can change with continued use, especially under conditions where the chromium oxide layer is altered (e.g. incompatible cleaners, abrasive cleaners, abrasive cleaning pads, or chlorine and related sanitizers). Therefore, it is recommended that surfaces be passivated (using nitric acid or other strong oxidizing agents) initially and on a regular frequency thereafter, to maintain a passive (non-reactive) oxide film on the surface. Passivation of stainless steel food contact surfaces is recommended after any surface repair, polishing, or working. –

Please contact Classic Electropolishing for help with food equipment passivation.


Electropolishing vs. Electroplating

We had a customer recently ask us the difference between electropolishing vs. electroplating. It’s quite simple we said. They are basically the exact opposite types of process. Electroplating pulls material onto the surface of the product you are working with. Electropolishing on the other hand removes material from the surface of the product you are working with.

That is the simple difference. We can get into more detail if you would like. Give us a call and we will break it down for you.


Polishing A Bean

For anyone who has visited Chicago in the last few years, Cloud Gate, a.k.a. “the bean” is a must see stop in Millennium Park:

the bean stainless steel finish

the bean stainless steel finish

It’s mirror like stainless steel finish and seamless design got us to wondering how it was finished and polished. There are so many nooks and crannies and odd spots that need to be cleaned in order to achieve such a brilliant mirror reflection. There is a wonderful description in Wikipedia for anyone who would like to build their own bean at home.

It is made up of 168 stainless steel plates welded together, and its highly polished exterior has no visible seams. It measures 33 by 66 by 42 feet (10 by 20 by 13 m), and weighs 110 short tons (100 t; 98 long tons). Every weld on the Cloud Gate underwent a five-stage process, required to produce the sculpture’s mirror-like finish.

Stage Name Equipment used Sandpaper type Purpose
1 Rough Cut 5-pound (2.3 kg), 4½-inch (110 mm) electric grinder 40-grit Removed welded seams
2 Initial Contour 15-pound (6.8 kg), 2-inch (51 mm), air-driven belt sander 80-grit, 100-grit and 120-grit Shaped the weld contours
3 Sculpting air-driven 10-pound (4.5 kg), 1-inch (25 mm) belt sander 80-grit, 120-grit, 240-grit and 400-grit Smoothed the weld contours
4 Refining double action sander 400-grit, 600-grit and 800-grit Removed the fine scratches that were left from the Sculpting stage
5 Polishing 10-inch (250 mm) electric buffing wheel 10 pounds (4.5 kg) of rouge Buffed and polished the surface to a mirror-like finish

The sculpture is expected to last 1,000 years. For maintenance, the lower 6 feet (1.8 m) of Cloud Gate is wiped down twice a day by hand, while the entire sculpture is cleaned twice a year with 40 U.S. gallons (33 imp gal; 150 L) of liquid detergent. The daily cleanings use a Windex-like solution, while the semi-annual cleanings use Tide.

If you reached this page and are interested in welding, there is a great post about comparing weld types here.

How would you like to be responsible for that finish. Pretty cool!


Medical Passivation

The process of medical passivation improves the surface of stainless steel medical products by dissolving iron that has been exposed during forming or machining. Without passivation, the iron can corrode and give the appearance of rust spots on the stainless steel products. The process of passivation gives medical products a longer shelf life with a higher level of quality. Our validated processes are certifiable to ASTM A967 which is a passivation standard.  Classic electropolishing has the ability to process all 300 and 400 series Stainless Steels, 17-4 Stainless Steel, titanium, and NiTinol.


Smooth As A Baby’s Electropolished Stainless Steel Bowl

Did you think we were going to say something else in our title? We have baby humor on our mind, Classic Electropolishing is a family owned business and our family just celebrated the one year birthday of our daughter!

Back to electropolishing though. How do electropolishers get their components so smooth like a babies you know what? The process of electropolishing basically takes more of of the microscopic peaks of the surface finish of your product. It also takes off materials from the microscopic valleys but not as fast.

Once completed, the smoother the finish the less room there is for impurities to form and be harbored in the product. The process also protects from corrosion and increases shelf life. Don’t hesitate to contact us with your smooth electropolishing needs.