The following is a summary of the steps and methods of polishing brushed stainless steel, combining the characteristics and precautions of different processes:

First. Preparation before polishing

    1. Clean the surface

        It is necessary to thoroughly remove the oil, oxide layer and residual metal shavings on the surface of brushed stainless steel. Can be wiped with acetone, alcohol or special cleaning agent.

    2. Check the surface status

        There should be no bumps or burrs on the surface after drawing. Otherwise, smooth the surface with 60-180 mesh sandpaper or ceramic fiber grinder.

Second, polishing method selection

    1. Mechanical polishing (mainstream method)

        Steps and Tools:

        ●  Rough polishing: Use 120# sanding belt or sandpaper to evenly sand until the surface color is consistent.

          Medium casting: Change the 240# sanding belt to continue polishing and eliminate the rough casting marks.

          Fine casting: Gradually upgrade to 800#, 1200# sanding or sandpaper, and finally achieve a smooth surface.

          Mirror finish (optional) : Use wool wheel +3M polishing wax or diamond grinding paste (particle size less than 1μm), polished in a circular motion to mirror effect.

      ●  Equipment parameters:

          The speed of the polishing machine is controlled at 1500-3500 RPM, the higher the speed, the stronger the gloss, but it is necessary to avoid burning the surface.

          The feed depth is recommended not to exceed 0.05mm each time, and the pressure should be uniform.

    2. Electrolytic polishing (suitable for mass production)

        Principle: Through electrolyte anodizing, dissolve the surface micro-protrusions, forming a uniform passivation film.

        Advantages: High efficiency, less pollution, suitable for complex shape workpieces.

        Limitations: requires professional equipment, high cost.

    3. Chemical polishing (suitable for small pieces or complex shapes)

        Steps: Immerse the workpiece in the polishing liquid based on nitric acid + hydrofluoric acid, smooth the surface through chemical reaction.

        Precautions: Ventilation equipment is required to avoid gas hazards, and thorough cleaning is required after treatment.

Third. Key points to note

    1. Order of polishing and drawing

        Must be polished before drawing. If it is necessary to polish twice after drawing, be careful to avoid damaging the original texture.

        Sandpaper/sanding belt selection

        Sandpaper model jumps no more than 3 grades (e.g. 180#→240#→400#).

        The drawing surface should keep the direction consistent to avoid cluttered lines.

    2. Surface protection

        After polishing, the surface can be protected by varnish or anti-fingerprint coating to prevent oxidation and scratches.

        Avoid mixing with non-stainless steel tools to prevent cross-contamination.

Fouth. Quality inspection standards

   ● Visual standard:

        Mirror effect: surface without scratches, fog spots, brightness up to 4-5 (clear reflection).

        Drawing texture: uniform grain, no broken line, defect point spacing > 10mm.

        Tools: Visual inspection at a distance of 45cm under fluorescent light, with both hands wearing gloves.

Five, efficiency improvement skills

        Pretreatment optimization: remove welds and burrs in advance to reduce polishing workload.

        Consumables management: Regularly filter the impurities of the polishing liquid to extend the service life.

        Equipment adjustment: Adjust the pressure and speed according to the material of the workpiece to avoid excessive grinding.

With the above method, the process can be flexibly selected for different needs, such as retaining the brushed texture or upgrading to a mirror. For high precision mirror effect, it is recommended to choose the combination of mechanical polishing and electrolytic polishing.