Tumbling (Vibration grinding)
Tumbling is a step of deburring and removing the edge.
Proper grinding removes damaged or deformed surface of material, while limiting the amount of additional surface deformation. The goal is to make the surface smooth with minimal damage in the shortest possible time.
Tumbling removes burrs by using abrasive particles. There are different shapes and materials of abrasive particles can be used that based on the products of material and surface roughness requirement. The tumbling process with suitable abrasive grains can produce the lowest amount of deformation, while providing the highest removal rate.
Polishing is used to remove the damage remaining from the grinding process to make the surface quality like mirror gloss. The surface roughness is under Ra0.2. This is achieved by successive steps with finer abrasive particles and tools.
Electropolishing is a chemical surface-finishing technique. The metal burrs or machining marks can be electrolytically removed from the surface. The primary purpose is to minimize the surface roughness, thus greatly reducing the risk of dirt or residues adhering and improving the cleanability of surfaces.
Electropolishing has become a common treatment for stainless steel in industries in which corrosion-resistance and cleanability requirements are particularly high. Typical applications are found in the pharmaceutical, biochemical and food-processing industries.
Since electropolishing doesn’t involve mechanical, thermal or chemical impact, small and mechanically fragile parts can be treated. Electropolishing can be applied to parts of almost any shape or size.
Anodizing (Type II) is a electroplating method of a metal part (mostly aluminum part) by forming a layer of oxide on its surface. It increases resistance to corrosion and wear, and provides better adhesion for paint primers (like screen printing) and glues than bare metal does.
The common used colors are nature (clear) and black. If any requirment about special colors, pls provide color samples for our production reference. Besides, Gloss difference is also divided into two types: bright(glossy) and matte.
Hard anodized, sometimes called Type III, offers greater corrosion protection and resistance to wear in extreme environments or frequent use. This is produced by continuing the electrical current until the depth exceeds 20 microns or even more. This takes more time and is more expensive but produces a superior result.
Zinc plating is typically used for screws and other fasteners, automotive parts, and various small parts that will be exposed in interior or mildly corrosive conditions. When a zinc coating is electroplated onto the surface of metals, it creates a formidable corrosion-resistant barrier.
For RoHS and REACH compliance, the specification ASTM B633 with trivalent chromate (Cr3+) conversion coating is common used. In addition, there are many different colors of zinc plating like white, blue, black and yellow. The main purpose is to prevent corrosion and provide aesthetic functions.