Capabilities · CNC Machining
CNC machining aluminum
Precision milling, turning and drilling of aluminum parts — from prototype to production. We hold tight tolerances on 3, 4 and 5-axis centers and combine machining with extrusion, bending and finishing in one build.
What CNC machining does for aluminum
CNC machining aluminum is subtractive: a programmed spindle removes material from a billet, plate or near-net extrusion to reach the final shape and tolerance. It is the step you reach for when a feature cannot be extruded, bent or cast — internal cavities, threaded holes, tight flatness, precision bores and complex 3D contours. Aluminum (especially 6061 and 6082) machines cleanly at high feed rates, so CNC is cost-effective even for parts with many features.
For build-to-print work, CNC is where the drawing meets the metal. We take your STEP or PDF, set datums, and hold the dimensions that matter — then pass the part to anodizing, powder coating or assembly without it leaving the project.
Typical equipment
- 3-axis vertical machining centers
- 4-axis indexers / rotary tables
- 5-axis simultaneous centers
- CNC lathes (turning)
- Wire / sinker EDM on request
Exact models and envelopes confirmed against your drawing.
How a CNC job runs
A consistent machined part comes from a disciplined sequence, not a single cut. Our typical flow:
- Program & setup. CAM generates toolpaths from your model; we choose fixtures and datums so critical features reference one stable origin.
- Roughing. High-feed removal of the bulk stock, leaving controlled margin for finish passes.
- Finishing. Light passes hold tolerance and surface finish; 5-axis lets us reach compound angles in one setup.
- Deburr & break edges. Manual or tumble deburr; edge breaks per your spec (sharp, 0.2 mm, or radius).
- Inspect. In-process checks plus final CMM or gauge verification against the drawing.
- Finish (optional). Anodize, powder coat, bead blast or pass to welding/assembly.
3, 4 or 5-axis — which to specify
Axis count decides how many setups a part needs. Fewer setups mean tighter relational accuracy between features and lower handling cost.
| Configuration | Best for | Why it matters |
|---|---|---|
| 3-axis | Plates, brackets, simple pockets | Fast and economical for prismatic parts |
| 4-axis | Parts with features around a rotation | One clamp, rotate to machine sides — fewer setups |
| 5-axis | Compound angles, impellers, contoured housings | Complex geometry in one setup, better surface and accuracy |
If your part has angled holes or curved faces, ask for 5-axis — it often removes a whole setup and the tolerance stack-up that comes with it.
Capability & typical specs
Numbers below are typical production ranges; confirm exact limits against your drawing. We control tolerance and verify per your spec.
| Parameter | Typical capability |
|---|---|
| Positioning tolerance | ±0.01 mm (typical) |
| Axes | 3 / 4 / 5-axis |
| Surface finish | Ra 0.8 µm achievable |
| Alloys | 6061 / 6063 / 6082 / 7075 (others on request) |
| Max part size | confirm against machine envelope |
| Secondary | anodize / powder coat / bead blast / weld |
CNC or extrusion — which first?
Many aluminum parts are a hybrid: extrude the long, constant cross-section shape, then CNC the features extrusion cannot make. Use this as a first cut:
| If you need… | Choose |
|---|---|
| Long constant section, thin walls, fins | Extrusion + post-machining |
| Tight internal cavities, threads, bores | CNC from billet / plate |
| Low volume, complex 3D shape | CNC (no tooling cost) |
| High volume, simple shape | Extrusion (tooling amortized) |
For a long finned heatsink, extrude the profile and CNC only the base mating face and mounting holes — that is usually the cheapest accurate route.
DFM notes for machined aluminum
Design for machining
- Standardize radii. Match inside corner radii to off-the-shelf end mills (e.g. 1, 2, 3 mm) to cut tool changes and cost.
- Avoid thin, tall walls. They chatter and flex; widen or add ribs where stiffness matters.
- Set datums and critical dims. Call out the features that must hold tolerance; we measure against those.
- Threads: prefer rolled or cut standard pitches; very fine threads in soft alloy need care — mask or form after anodize if tolerance is tight.
- Deep pockets: limit depth-to-width ratio; deeper needs longer tools, more chatter, higher cost.
- Tolerance only where needed. Default to ISO 2768-m unless a feature is functional — every tight tolerance adds inspection and scrap risk.
Alloy notes
Machinability and finish vary by alloy. Plan the alloy at the design stage:
| Alloy | Machining note |
|---|---|
| 6061 | Excellent all-round; clean chips, good finish, the default for machined parts |
| 6082 | Similar to 6061, common in EU projects; slightly higher strength |
| 6063 | Good, softer — fine for light machining, less stiff than 6061 |
| 7075 | Machines well but higher cost; use where strength-to-weight is critical |
Other grades available on request; we confirm finish and tolerance against alloy and quantity before quoting.
Where machined aluminum is used
Electronics & enclosures
Front panels, brackets, heatsink bases, connector blocks — tight holes and flatness for seals.
Heat sinks
CNC-machined sinks for complex geometry and low volume; base fly-cut for flat contact.
Automation & fixtures
Jigs, guide rails, sensor mounts where repeatability matters.
Medical & lab
Instrument parts needing clean finish and documented material.
Frequently asked questions
What tolerance can CNC hold in aluminum?
Typical positioning tolerance is around ±0.01 mm on well-fixtured features; we regularly hold ISO 2768-f/m defaults and tighter on called-out dims. Actual achievable tolerance depends on part size, feature relation and alloy — confirm against the drawing during DFM review.
When should I choose 5-axis over 3-axis?
Choose 5-axis when the part has compound angles, curved surfaces or features on multiple faces. It machines them in one setup, which removes the tolerance stack-up from repeated clamping and usually lowers cost on complex parts. Simple plates are fine on 3-axis.
CNC from billet or machine an extrusion?
For long constant sections with fins or thin walls, extrude then CNC only the features extrusion cannot make — cheaper and faster. For low-volume complex 3D shapes with internal cavities, machine from billet to skip tooling cost. Send the drawing; we advise the route.
Which alloy machines best?
6061 is the default — clean chips, good finish, widely available. 6082 is similar and common in EU projects; 7075 machines well but costs more and is used where strength matters. 6063 is fine for light machining.
Can you machine and then anodize?
Yes, and it is common. Machine to final size, then anodize; mask any feature that must hold a tight tolerance because the oxide adds ~1–3 µm. We coordinate machining and finishing so masked features stay in spec.
What files do you need for a quote?
A STEP or PDF with dimensions, alloy, quantity, tolerance callouts and required finish. The more complete the drawing, the tighter our quote. For DFM feedback, a 3D model plus critical-dim list is ideal.
Machine your aluminum parts
Send STEP/PDF and quantities — we quote machining, finishing and assembly as one job.