Electropolishing is an electrochemical finishing process that removes a very thin layer of metal from a component’s surface. It is most often used on stainless steel to reduce microscopic roughness, remove light surface contamination, and refine small burrs or projections.

Unlike grinding or buffing, electropolishing does not smooth the surface through abrasive contact. Material is dissolved electrochemically, with raised microscopic features removed more readily than recessed areas. That selective removal gives the process its characteristic leveling effect.

High Purity Technology (HPT) provides electropolishing services for 304, 316, and 400-series stainless steel and alloys, with capabilities covering tube, fittings, pipe, tanks, pumps, flanges, and other components and systems.

How Does Electropolishing Work?

During electropolishing, the metal component is immersed in an electrolyte solution and exposed to direct electrical current. The electrochemical process removes metal ions along with surface contaminants, producing a smoother and cleaner finish.

This separates electropolishing from mechanical finishing methods such as grinding or buffing. Because the surface is refined electrochemically rather than through abrasive contact, the process can reduce roughness and avoid introducing the scratches or debris associated with mechanical polishing. 

What Are the Benefits of Electropolishing?

Electropolishing alters the exposed metal surface in several useful ways, from smoothing microscopic irregularities to improving cleanliness and corrosion resistance. Benefits include: 

• Improved corrosion resistance: Helps protect stainless steel against rust and oxidation.
• Reduced surface roughness: Removes microscopic high points to create a smoother, more uniform finish.
• Deburring and edge rounding: Reduces fine burrs and sharp projections left on the surface.
• Enhanced passivation: Supports a more uniform passive layer on stainless steel.
• Surface contaminant removal: Removes contaminants from the outer metal surface and improves cleanliness.

A bright, mirror-like appearance may accompany the process, while the more important gains are tied to surface condition, cleanliness, and corrosion resistance.

Where is Electropolishing Used?

HPT provides electropolishing services for medical, pharmaceutical, food and beverage, aerospace, and semiconductor applications.

In these settings, electropolishing is used on stainless steel components such as tubing, fittings, process piping, tanks, pumps, flanges, and larger assemblies when the specified finish entails lower roughness, improved cleanliness, corrosion resistance, or a more uniform passive surface. 

What Can Be Electropolished?

Our electropolishing capabilities extend across both individual process components and larger fabricated equipment, including:

• Tube, fittings, pipe, and pipe fittings
• Tanks
• Racks, carts, and tables
• Pumps and flanges

The suitability of a part is contingent on the material, configuration, and finishing requirement, so we review each project against the component and the specified surface condition.

HPT Electropolishing Services

Our electropolishing services follow the HPT-100 specification, which meets ASTM B912-02 standards. We can also accommodate customized processing requirements based on customer needs.

After electropolishing, components are inspected by trained personnel, bagged and labeled, and supplied with certification of conformance. Electropolished material is packaged in our Class 10,000 cleanroom.

Expedited electropolishing services are also available when shorter lead times are required.

Frequently Asked Questions (FAQs)

What is electropolishing?
Electropolishing is an electrochemical process that removes metal ions, surface contaminants, and micro-roughness to produce a smoother, cleaner metal surface.

How does electropolishing differ from mechanical polishing?
Electropolishing uses electrochemistry to remove metal; mechanical polishing relies on grinding or buffing. Mechanical methods can leave scratches or debris behind.

Does electropolishing improve corrosion resistance?
Yes. Improved resistance to rust and oxidation is among the principal benefits of electropolishing.

What industries use electropolishing?
The HPT team provides electropolishing services for medical, pharmaceutical, food and beverage, aerospace, and semiconductor sectors.

What materials does HPT electropolish?
HPT provides electropolishing for 304, 316, and 400-series stainless steels and alloys.

Talk With HPT About Electropolishing

Electropolishing offers a precise way to refine stainless steel and alloy surfaces by reducing micro-roughness, removing surface contamination, improving corrosion resistance, and enhancing passivation.

HPT provides electropolishing services for tubing, fittings, pipe, tanks, pumps, flanges, and larger systems, with processing available to HPT-100 or customer-specific requirements.

Connect with our team to discuss your component, surface-finish goals, and electropolishing requirements.