Electropolishing
电解抛光
Electrochemical smoothing for bright, clean stainless steel surfaces, with controlled material removal for precision components.
Electropolishing is an electrochemical surface-finishing process that selectively removes metal from microscopic high points. The part acts as the anode in an electrolytic cell, smoothing the surface while producing a bright, clean finish. For stainless steel components, the process also supports formation of a passive, chromium-rich surface.
How Electropolishing Changes a Stainless Steel Surface
Unlike electroplating, electropolishing removes material rather than depositing a coating. Surface peaks are removed faster than lower areas, which can reduce roughness, soften micro-burrs, and make the surface easier to clean. The final appearance and roughness depend on the starting finish, alloy, geometry, weld condition, and the amount of material that can be removed.
Electropolishing Stainless Steel and Other Supported Materials
Active Treatment electropolishes 300-series and 400-series stainless steels, as well as aluminium and copper alloys. Stainless steel is a common choice for electropolishing where a component needs a smoother, brighter surface together with passivation. Material grade must be confirmed because different alloys and starting conditions do not produce identical colour, brightness, or roughness results.
Surface Finish and Dimensional Considerations
Typical total metal removal is 5–40 µm across both sides, and surface roughness may be reduced by up to 50% from the starting condition. A representative improvement is from Ra 0.8 µm to around Ra 0.2 µm, but the achievable result must be assessed from the incoming surface and component geometry. Drawings should identify close-tolerance diameters, sealing faces, threads, edges, and any surfaces that require masking or controlled removal.
What Electropolishing Can and Cannot Correct
Electropolishing is effective for microscopic peaks, fine machining marks, and small burrs. It does not level deep scratches, pits, heavy weld defects, scale, or major surface damage. Components with visible defects may require suitable preparation before electropolishing, and a sample or first-off inspection may be appropriate when appearance is critical.
Electropolishing, Mechanical Polishing and Passivation
Electropolishing is selected when smoothing, brightness, cleanability, and passivation are required together. Mechanical hairline buffing and polishing creates a directional cosmetic finish and may be needed before electropolishing when deep marks must be removed. Stainless steel passivation is the better fit when the requirement is free-iron removal without intentional smoothing or brightening.
Industrial Electropolishing Applications
The service is used for stainless steel components in medical, pharmaceutical, semiconductor, and food-processing applications where surface condition and cleanability matter. Typical evaluation points include starting and target roughness, accessible geometry, weld condition, edge requirements, material-removal allowance, visual finish, and the required inspection or documentation.
What to Provide for an Electropolishing Quote
Provide the material grade, drawing and dimensions, quantity, starting surface condition or Ra value, target finish or Ra requirement, permitted metal removal, critical dimensions, masking requirements, weld and assembly details, cosmetic expectations, inspection or documentation requirements, and required delivery date.
Key Benefits
- Reduces surface roughness by up to 50% from the starting condition
- Produces a bright, smooth surface finish
- Combines micro-smoothing with stainless steel passivation
- Reduces microscopic peaks and small burrs
- Supports easier cleaning through a smoother surface
- Controlled material removal for precision requirements
Specifications
| Substrate | 300-series stainless, 400-series stainless, aluminium, copper |
|---|---|
| Metal removal | 5–40 µm total across both sides |
| Result variables | Starting finish, alloy, geometry, weld condition, removal allowance |
| Typical Ra improvement | From 0.8 µm to around 0.2 µm |
| Surface roughness reduction | Up to 50% from the starting condition |
Frequently Asked Questions
What is electropolishing stainless steel?
Electropolishing is an electrochemical process that removes a controlled amount of metal from microscopic surface peaks. On stainless steel it can reduce roughness, brighten the surface, soften small burrs, and support formation of a passive chromium-rich surface.
How much metal does electropolishing remove?
Typical total removal is 5–40 µm across both sides. The appropriate allowance depends on the material, geometry, starting finish, and critical dimensions, so these requirements should be identified on the drawing before processing.
Is electropolishing the same as mechanical polishing?
No. Mechanical polishing uses abrasives to cut and blend the surface and normally leaves a directional finish. Electropolishing removes metal electrochemically from microscopic high points, producing a smoother, non-directional result.
Can electropolishing remove deep scratches?
Electropolishing can reduce fine machining marks and microscopic surface peaks, but it will not level deep scratches, pits, heavy weld defects, or major surface damage. Those conditions may require preparation before electropolishing.
Should I choose electropolishing or passivation?
Choose electropolishing when the part needs smoothing or brightening together with passivation. Choose chemical passivation when the main requirement is free-iron removal without intentional material removal, smoothing, or a brighter finish.
What Ra surface finish can I expect after electropolishing?
A representative improvement is from Ra 0.8 µm to around Ra 0.2 µm, and roughness may be reduced by up to 50% from the starting condition. The result depends on alloy, geometry, starting finish, and permitted removal, so target Ra should be reviewed before quotation.
What information is needed for an electropolishing quote?
Provide the material grade, drawing, dimensions, quantity, starting and target Ra, permitted metal removal, critical dimensions, masking needs, weld and assembly details, cosmetic expectations, inspection requirements, and delivery date.
Request a Quote
Contact Active Treatment Pte Ltd in Singapore for Electropolishing. Call +65 6352 9846 or email activetreatment88@yahoo.com.sg.