Ten Common Surface Finishes for Machined Parts
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01AS-MACHINED STANDARD PROCESSFastest lead time; parts retain visible tool marks and inherent burrs/sharp edges (burrs removed upon request); surface roughness Ra 125 μin; no additional surface finishing costs.
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02SANDBLASTINGCreates a uniform matte texture across the entire surface; removes tool marks and surface imperfections to enhance aesthetic appeal.
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03TUMBLE FINISHINGBatch-processing method for vibratory deburring and removing tool marks; ideal for mass production of small parts; parts with an outer diameter > 8 inches require manual dimensional inspection after finishing.
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04ALUMINUM ANODIZING TYPE II / TYPE III HARDType II creates a thin, corrosion-resistant layer available in clear, black, red, and gold colors; Type III (Hard Anodizing) produces a thicker oxide layer offering superior corrosion resistance and wear resistance (applicable only to aluminum alloys).
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05CHROMATE CONVERSION COATING MIL-DTL-5541Forms a thin film (0.00001–0.00004 in) with a golden-yellow or light-yellow hue; provides excellent corrosion resistance and electrical conductivity; commonly used as a primer for painting.
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06STAINLESS STEEL PASSIVATIONSuitable for 200-series, 300-series, and precipitation-hardening stainless steels; creates an extremely thin oxide layer (approx. 0.0000001 in) that enhances the material's corrosion resistance without altering the part's dimensions.
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07POWDER COATINGDry powder is applied via electrostatic spraying and then cured at high temperatures; the resulting paint film is tough, wear-resistant, and corrosion-resistant; available in a wide range of colors with superior adhesion compared to conventional liquid painting.
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08ELECTROPOLISHINGAn electrochemical brightening treatment for stainless steel; removes 0.0001–0.0025 in of base material to achieve a mirror-like finish and reduce potential corrosion risks.
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09TUMBLE FINISHINGA non-electrolytic plating process that ensures uniform coating thickness—even on parts with complex geometries; features a bright finish with a standard initial thickness of 0.0001 in; offers excellent corrosion and wear resistance.
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10HOT-DIP / ELECTRO-GALVANIZING ASTM B633-15Provides complete zinc coverage on steel components, ensuring a uniform coating even on complex structures; primarily designed to deliver long-term rust prevention and protection for carbon steel.