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.

  • Precision without polish
  • Functional and cost-effective
  • Sharp details, clean cut

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

  • Simplify Geometry Where Possible: Reducing overly complex features and loosening non-critical tolerances can help ensure more consistent surface finishes and reduce machining time.

  • Refine Tooling and Toolpaths: High-quality, sharp tools and optimized toolpath strategies are essential to minimize tool chatter and achieve a better surface finish.

  • 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 ValuesHarbin 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

Faster Turnaround

Parts ship straight from CNC machining—no need to wait for secondary finishing. This cuts lead times by days or even weeks compared to polished or coated surface treatment, which makes it ideal for rapid prototyping or urgent production runs.

Cost Efficiency

As machined finish eliminates grinding, blasting, and other post-processing expenses. You only need to pay for machining time and material, making it the most budget-friendly option. Perfect for high-volume production or internal components that have low aesthetic requirements.

Dimensional Accuracy

It maintains original tolerances by design without post-machining distortion, which is critical for precision assemblies where even minor material removal (like from polishing) could affect fit. Often used for jigs, bearings, and mating surfaces.

Functional Flexibility

Works equally well for (major) metals and plastics. The uniform tool-marked surface can improve lubrication retention in moving parts. Ready to use as-is, or easily upgraded with other finishes or treatments later.

Frequently Asked Questions