As Machined Finish Services
Need parts fast and cost-effective? Our As Machined finish delivers components directly from CNC machining. You get precise tolerances, clean edges, and a surface free of burrs with consistent tool marks. Ideal for functional prototypes or parts inside assemblies, it’s ready to use right away or serves as a great base for additional finishing.
As Machined Overview
As Machined Surface Finish refers to the surface condition of a part directly after CNC machining, without any additional polishing, coating, or other finishing processes. It retains the natural tool traces and marks from the cutting tools, resulting in a slightly rough texture but high dimensional accuracy. I is commonly used for functional prototypes, internal components, or parts where the priority is not aesthetics but performance and cost-efficiency.
Because it skips secondary treatments, the As Machined finish saves both time and money. Surface roughness typically falls around Ra 3.2 μm (125 µin), though this can vary depending on the material and machining method. Despite the visible tool marks, most parts are lightly deburred to remove sharp edges, making them safe to handle, which makes it a practical choice when tolerances and functionality outweigh the need for cosmetic appearance.
But if your parts weigh aesthetic performance more than tolerance integrity, you might need Additional Surface Treatment instead of As Aachined Finish.
As Machined Surface Finishes Comparison
| Surface Roughness | Applicable Materials | Cosmetic Availability | Description |
|---|---|---|---|
| Ra 3.2 μm | Metals, Plastics | No | Standard machining with basic cleaning, deburring, and edge breaking. No additional surface treatment is applied. Tool marks are visible. |
| Ra 1.6 μm | Metals, Plastics | No | Achieved through finer machining settings. Offers a smoother surface than Ra 3.2 μm, with visible but reduced tool marks. Also includes basic cleaning and deburring. |
As Machined Design Considerations
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Simplify Geometry Where Possible: Reducing overly complex features and loosening non-critical tolerances can help ensure more consistent surface finishes and reduce machining time.
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Refine Tooling and Toolpaths: High-quality, sharp tools and optimized toolpath strategies are essential to minimize tool chatter and achieve a better surface finish.
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Choose Suitable Materials: Select materials known for good machinability and favorable surface characteristics to improve finish quality without requiring secondary processing.
Lathe Surface Roughness Data Sheet
| Speed | Feed | Finish | Speed | Feed | Finish |
|---|---|---|---|---|---|
| -1 | -1 | 7 | -1 | -1 | 9 |
| -1 | 0 | 77 | -1 | 0 | 77 |
| -1 | 1 | 193 | -1 | 1 | 190 |
| 0 | -1 | 7 | 0 | -1 | 9 |
| 0 | 0 | 75 | 0 | 0 | 80 |
| 0 | 1 | 191 | 0 | 1 | 191 |
| 1 | -1 | 9 | 1 | -1 | 18 |
| 1 | 0 | 79 | 1 | 0 | 80 |
| 1 | 1 | 192 | 1 | 1 | 190 |
* Speed: Unit: r/min (revolutions per minute). Negative values are experimental codes (require conversion to actual values); Feed: Unit: mm/r (millimeters per revolution). Negative values are experimental codes; Finish (Surface Roughness): Unit: μm (micrometers), expressed as Ra (Arithmetical Mean Deviation of the profile).
Data Sourse: Extracted from Table 9.16 (Industrial Statistics-Ronald Christensen and Aparna V. Huzurbazar-Department of Mathematics and Statistics University of New Mexico).
Notes:
- Roughness Standard: Complies with *ISO 21920-1:2021 (Surface Roughness Parameters and Values)*.
- Typical Reference Values: Harbin Measuring & Cutting Tool Group (HALI) Surface Roughness Samples (Ra 0.8–6.3 μm).
- Negative Value Handling:
*Speed = -1* and *Feed = -1* are experimental codes. *Convert to physical values using specified formulas (e.g., Speed range: 200–2000 r/min).* - Outliers:
*Finish = 77 μm* may result from tool wear or excessive feed rate (normal finish turning range: Ra 0.8–1.6 μm). - Precision Class:
Ra ≤ 1.6 μm requires high-precision lathes (reference standard: IT7 tolerance grade).
Benefits of an As Machined Surface Finish
Frequently Asked Questions
At KingStar Mold, we follow strict machining standards, use high-quality cutting tools, and maintain optimized toolpaths. Our in-house quality team inspects each batch for surface roughness, dimensional accuracy, and defect-free finishes to ensure consistency every time. For more information about our quality assurance system, please refer to this page: Manufacturing Quality Control for Precision Parts.
No. As Machined finishes are applied directly after precision CNC machining, so they preserve dimensional accuracy without additional material removal. That’s exactly why they’re ideal for parts requiring tight tolerances.
Yes, we can accommodate specific surface roughness requirements like Ra 3.2μm, Ra 1.6μm, or even Ra 0.8μm by adjusting the final cutting pass. Let us know your functional or aesthetic needs when placing your order (you may also refer to the datasheet we provided on this page above).
Generally, no. Parts delivered as machined may show tool marks or traces and aren’t intended for cosmetic use. If visual appearance is important, post-processing such as polishing, bead blasting, or anodizing is recommended.
“As Machined” refers to the surface that has undergone only the initial processing and has not undergone any further treatment. “As” here is not an abbreviation for other terms; other similar expressions include “As Cast”, “As Milled”, “As Printed”… The surface is typically cleaned, deburred, and has visible tool paths or machining marks, with a surface roughness usually around Ra 3.2μm or Ra 1.6μm.
