What is metal polishing?
Polishing uses progressively selected abrasives to refine accessible metal surfaces. Visual brightness and measured roughness are different requirements and should be specified independently. Geometry, starting condition and the permitted material removal determine the suitable finishing route.
Key specifications
Process references and example callouts are identified below. CHIHENG confirms the accepted material, dimensions and treatment requirements in the part quotation.
| Parameter | Reference / what to specify |
|---|---|
| Materials | Suitable grades of stainless steel, aluminium, brass and other metals. |
| Texture requirement | Appearance sample and/or measured surface parameter; Ra 0.8 µm is an example requirement, subject to review. |
| Tolerance | Control material removal on fitted diameters, sealing features, edges and markings. |
| Film thickness | Not applicable to mechanical polishing; specify any later coating separately. |
| Colour / measurement | Natural metal appearance; define measurement direction and conditions where texture is functional. |
| Size / reference | Review abrasive access and handling; ISO 21920-1 addresses surface-texture indication. |
Technical references: ISO 21920-1:2021: surface-texture indication
Applications
Industrial hardware
Visible fittings and knobs with a defined cosmetic surface.
Fluid-handling equipment
Accessible metal surfaces with customer-specified texture and edge requirements.
Custom products
Aluminium or brass components requiring a refined visible finish.
Working with CHIHENG
A direct conversation with our team, from your first drawing to delivery.
A reply within 24 hours
Send us your drawing and questions. Our team will reply within 24 hours and help you work out the next step.
An experienced engineering team
Talk through materials, tolerances and finishing with engineers who understand how your part will be made.
Machining equipment
We use our machining equipment and practical manufacturing experience to turn your drawings into finished parts.
Competitive worldwide shipping
We offer competitive shipping solutions for customers around the world, with options to suit your destination and delivery schedule.
Process steps
- Agree visible faces, starting condition, sample and any measured texture requirement.
- Protect critical geometry and select a substrate-compatible abrasive sequence.
- Refine the agreed surfaces while controlling edge rounding and material removal.
- Clean and inspect appearance, specified texture and retained dimensions.
Metal polishing vs Brushing
| Comparison point | Metal polishing | Brushing |
|---|---|---|
| Appearance | Progressively refined or bright surface | Deliberate directional grain |
| Acceptance | Sample and/or measured texture requirement | Direction drawing, sample and any texture requirement |
| Material removal | Control edges, fits and markings | Control edges, fits and markings |
| Selection | Choose for surface refinement or a specified visual result | Choose when grain direction is part of the design |
Specifying a polished finish
- Show the surfaces to be polished and send a sample or appearance reference.
- If surface roughness matters, include a measured requirement as well as terms such as bright or mirror.
- Mark fits, sealing faces, engravings and deep recesses so we can review access and material removal.
FAQ
Does polished always mean a mirror finish?
No. Polished surfaces can have different appearances. Provide a sample or an explicit appearance requirement rather than relying on the name alone. Identify final dimensions and any permitted finishing allowance. The inspection sequence needs to cover the polished geometry, not only the component before material is removed.
Does a shiny surface prove a roughness value?
No. If roughness matters functionally, specify the value and the inspection requirement separately from the visual appearance. Define the parameter, measurement direction and acceptance conditions on the drawing. Use a sample separately for appearance rather than treating reflection as a measurement result.
Can only selected faces be polished?
Identify the faces and boundaries on the drawing. Include any neighbouring surfaces, edges or markings that need protection. A sample alone does not define the acceptable edge condition or fit. Include the final dimensions and inspection requirements for neighbouring features in the same enquiry.
Can polishing remove deep tool marks?
Removing a deep machining mark may require more material removal than the drawing permits. Provide the starting condition, cosmetic faces and final dimensional limits before choosing the finishing route. A reference sample defines the desired appearance, but does not authorise changes to fitted geometry or guarantee that every defect can be polished away.
How do I specify the polishing extent?
Mark the faces requiring polishing and the boundaries against adjacent surfaces. Identify sharp edges, lettering, fitted features and any sealing areas that must remain controlled. Add the appearance sample and any measured texture requirement so the quotation defines both the finish target and the geometry that cannot be altered during polishing.
