- Ellyn@tenghui-proto.com
- +86-18666887162
From rapid prototypes and low-volume runs to full-scale production, our vertical and horizontal machining centers support parts with complex geometries, multiple machined features, and a wide range of sizes. With advanced 3-axis and 4-axis CNC milling capabilities, we produce custom metal and plastic components with consistent quality and tolerances down to ±0.01 mm for selected critical features.
We mill certified aerospace and commercial grade metals and plastics with full material traceability certificates upon request.
Lightweight, highly machinable, corrosion-resistant, and available in high-strength and anodizing-friendly grades.
Housings, brackets, frames, heat sinks, electronic enclosures, fixtures, aerospace parts, and functional prototypes.
Anodizing, hard anodizing, conversion coating, powder coating, bead blasting, polishing, and laser marking.
Aluminum 6061 / 7075
Lightweight, impact-resistant, easy to machine, and cost-effective, with good dimensional stability and electrical insulation.
Electronic enclosures, equipment housings, control panels, functional prototypes, consumer products, automotive interior parts, and fixtures.
As-machined, sanding, mechanical polishing, painting, and laser marking upon request.
ABS Rigid Engineering Plastic
CNC milling tolerances define the permitted variation between a specified dimension on the technical drawing and the measured dimension of the finished part. Tighter tolerances may require additional machining time, controlled setups, suitable materials, and more extensive inspection, which can affect production cost and lead time.
Tolerance Level | Metric Tolerance | Imperial Tolerance | Typical Applications |
Standard Machining | ±0.05 mm | ±0.002 in | General dimensions, brackets, housings, plates, fixtures, and structural components |
Precision Machining | Down to ±0.01 mm | Down to ±0.0004 in | Selected critical features, locating surfaces, precision holes, mating components, and assembly interfaces |
Geometric Tolerances | Drawing-dependent | Drawing-dependent | Flatness, parallelism, perpendicularity, position, concentricity, and profile requirements |
Achievable tolerances depend on the material, part size, geometry, feature accessibility, wall thickness, machining process, surface finish, and inspection method. Please identify all critical dimensions and geometric tolerances on your 2D drawing so our engineering team can review and confirm them before production.
Follow these general design guidelines to improve machinability, shorten production time, and control machining costs. These values are recommended starting points rather than fixed manufacturing limits. Final feasibility depends on the material, geometry, part size, tolerances, and surface-finish requirements.
Design Feature | Recommended Guideline | Practical Considerations |
Minimum Wall Thickness | Metals: ≥0.8 mm; plastics: ≥1.5 mm | Thin walls may vibrate, deflect, or warp during machining. For tall walls, large parts, and soft plastics, greater thickness may be required. |
Minimum Hole Diameter | ≥1.0 mm; standard drill sizes preferred | Smaller holes are possible for selected parts but require delicate tools, slower machining, and additional process control. |
Hole Depth | Preferably ≤5× the hole diameter | Holes deeper than 5×D may require extended-length drills, staged drilling, or specialized deep-hole processes. Through-holes are preferred when possible. |
Blind-Hole Depth | Allow an additional drill-point depth of approximately 0.3× the hole diameter | A standard drill produces a conical bottom. Specify the required full-diameter depth rather than only the total drilled depth. |
Pocket Depth | Preferably no more than 4× the pocket width | Deep, narrow pockets require longer tools and may increase vibration, tool deflection, machining time, and surface variation. |
Internal Corner Radii | Minimum radius: 1.0 mm; preferably ≥⅓ of the pocket depth | Larger internal radii allow the use of stronger cutting tools, reduce machining time, and improve corner surface quality. |
Floor Radii | ≥0.5 mm where permitted | A small floor radius can improve tool access and reduce stress concentration. Specify sharp floor transitions only where functionally required. |
Text and Engraving | Character height ≥2.0 mm; stroke width ≥0.5 mm; depth 0.2–0.5 mm | Use simple sans-serif fonts with adequate spacing. Smaller text may be possible but requires an engineering review. |
Dimensional Tolerances | Standard: ±0.05 mm; down to ±0.01 mm for selected critical features | Apply tighter tolerances only to functionally critical dimensions, mating surfaces, locating features, and precision holes. |
Surface Roughness | Standard as-machined finish: approximately Ra 1.6–3.2 μm | Finer finishes may require additional tool passes, polishing, grinding, or other secondary operations. |
Undercuts | Avoid where possible; use standard dimensions when required | Undercuts require specialized cutters and additional tool access. Custom undercuts may increase machining time and cost. |
Threaded Holes | M3 or #4-40 and larger preferred | Smaller threads can be produced for suitable parts but carry a higher risk of tap breakage and thread damage. Use standard thread sizes whenever possible. |
Thread Engagement | Metals: approximately 1–1.5× the nominal thread diameter; plastics: approximately 2×D | Excessive thread depth generally adds machining difficulty without providing a proportional increase in joint strength. |
Tapped Blind Holes | Provide unthreaded clearance beyond the required full-thread depth | Extra depth is needed for the tap lead and chip clearance. Clearly specify the required full-thread depth on the 2D drawing. |
Feature Accessibility | Design features for access from as few orientations as practical | Reducing machining orientations and setups can shorten lead times and improve feature-to-feature consistency. |
Surface Finishes | Apply special finishes only to required surfaces | Tight roughness, cosmetic, or coating requirements on every surface can unnecessarily increase machining and inspection costs. |
Maximum Part Size | Up to 3000 × 2000 × 100 mm or 4500 × 600 × 100 mm | Maximum capacity depends on the part geometry, material, feature locations, tolerances, machining direction, and workholding requirements. |
These guidelines are intended for general reference. Please submit your 3D CAD model and fully dimensioned 2D drawing for a project-specific DFM and machining feasibility review.
High-precision subtractive manufacturing engineered for mission-critical metal and plastic parts. Discover how TENGHUI integrates DFM engineering, multi-axis agility, and strict metrology.
CNC milling is an advanced subtractive manufacturing process that removes material from raw solid billets, plates, or castings using computer-guided rotary cutting tools. Toolpaths are digitally generated directly from 3D CAD geometries, while 2D technical drawings control tight tolerances, surface textures, threads, and datum alignment.
High-Speed Multi-Axis Milling
DFM Design for Manufacturability
Milling expenditures are primarily driven by cycle time, raw stock machinability, setup frequency, surface finishes, and batch quantities. Our engineers evaluate drawings to recommend actionable cost-saving optimizations:
Common machining defects—such as stress warping, tool deflection, harmonic chatter, and surface irregularities—are mitigated through rigid workholding, thermal drift compensation, and standardized in-process checks.
Quality-Controlled Production Workshop
50+ CNC Machines & Material Inventory
Equipped with 50+ CNC machines across 3-axis, 4-axis, and 5-axis setups, TENGHUI supports prototypes, low-volume runs, and serial production orders for custom metal and plastic parts.
Send us your 3D CAD files (STEP, IGES) and 2D drawings for engineering review and quotation:
Our large-part CNC milling capabilities accommodate parts up to 3000 × 2000 × 100 mm, as well as long components up to 4500 × 600 × 100 mm. Actual capacity depends on the part geometry, material, feature locations, tolerances, machining direction, and workholding requirements. Please submit your 3D model and 2D drawing for a feasibility review.
Yes. We regularly machine thin-walled enclosures, housings, brackets, and other components. As a general guideline, we recommend minimum wall thicknesses of 0.8 mm for metals and 1.5 mm for engineering plastics.
Thinner walls may be possible depending on the material, wall height, geometry, tolerances, and workholding method, but they may increase the risk of vibration, deflection, and deformation.
Because CNC milling uses rotating cutting tools, perfectly sharp internal corners cannot be produced directly with standard milling cutters. We generally recommend internal corner radii of at least 1.0 mm, with larger radii preferred for deeper pockets.
Deep and narrow pockets may require longer tools, additional machining passes, or EDM, increasing machining time and the risk of tool deflection. Our engineers will review these features and recommend a suitable process.
CNC milling uses rotating cutting tools to machine a stationary workpiece and is ideal for plates, brackets, housings, pockets, holes, and parts with multiple flat or contoured features. CNC turning rotates the workpiece against a cutting tool and is generally better suited to shafts, pins, bushings, sleeves, and other cylindrical parts.
Components containing both turned and milled features may require live-tool turning or a combination of both processes.
Five-axis CNC milling is well suited to parts with complex contours, angled features, deep cavities, undercuts, or critical features located on multiple sides. By accessing more surfaces in fewer setups, it can reduce manual repositioning and improve feature-to-feature consistency.
However, not every part requires five-axis machining. We select 3-axis, 4-axis, or 5-axis machining according to the part geometry, tolerance requirements, quantity, and overall manufacturing cost.
If you have any questions or would like to book a session please contact us.
Once we receive your design files, our senior manufacturing engineers will manually perform a comprehensive DFM review and deliver an accurate, optimized quote within 24 hours.
