Aluminum Extrusion: 6063 Profiles to ±0.05 mm
Extrusion is a near-net process. The die forms the wall, the fins and the bore in one pass, so machining only removes what the tolerance actually requires — that is where the 90% reduction in cut material comes from.
- Profile section
- ±0.05 mm
- Wall thickness capability
- ±0.02 mm
- Minimum wall
- 0.3 mm
- Die lead time
- 4–5 days
Why extrusion uses less material than milling
Milling a housing from solid billet means buying a block and turning most of it into chips. On a typical enclosure, the finished part is a small fraction of the starting block, and every kilogram of swarf was paid for twice — once as metal, once as machining time.
Extrusion inverts that. The die produces a cross-section that is already close to the finished wall, so the machining allowance is measured in tenths of a millimetre instead of centimetres. Our process route removes roughly 90% less material than the equivalent solid-billet job.
The second gain is metallurgical. Extruded 6063 is wrought: it is dense and free of the gas porosity that die casting tolerates. That is why a 0.3 mm wall is possible here and not in a cast part.
The dimensional claim is not a brochure number. Our internal standard Q/FD 001-2026 holds main functional surfaces to ±0.05 mm on the section, against ±0.15 mm in GB/T 5237.1 high-precision grade. The full dimensional comparison is published in the Q/FD 001-2026 tolerance table.
Extrusion facts
- Profile cross-section ±0.05 mm, versus ±0.15 mm in GB/T 5237.1 high-precision grade
- Wall thickness capability ±0.02 mm, minimum 0.3 mm
- Bore and OD ±0.04 mm after machining
- 2 fully automated extrusion lines
- Die in 4–5 days, first sample in about 7 days
- Alloys: 6063-T5 / T6, 6061-T6, 6005A
How a profile becomes a finished housing
Six stages. The first two decide whether the last four can hold tolerance.
-
Billet heating
6063 or 6061 logs are heated to extrusion temperature and pushed through the die. Temperature control here decides surface quality and dimensional stability later.
-
Die and profile design
We design the die around your finished part, not around a standard profile. Wall thickness, fin ratio and corner radii are agreed before the die is cut — this is where most DFM feedback lands.
-
Extrusion and quench
The profile exits and is cooled under controlled conditions. Cooling rate sets the temper response and helps prevent internal stress that would move a thin wall during machining.
-
Cutting and ageing
Profiles are cut to length and aged to T5 or T6. Dimensional checks happen on the cut length, because a profile that measures well at the die can still bow over 3 m.
-
Machining the features
Bores, sealing faces, threads, hinge pockets and ports are cut to ±0.01 mm. Stress relief between roughing and finishing keeps 0.3 mm walls where the drawing put them.
-
Finishing and inspection
180# bead blast and anodizing without polishing, then dimensional and appearance inspection against the approved sample and color chip.
The extrusion hall in Shenzhen: two automated lines, 5,000 m² production floor and 3,000 m² of warehouse alongside.
Extruded + Machined vs. CNC From Solid vs. Die Cast: Eight Dimensions
The same part, three process routes. Read down the columns for the dimension that decides your case. We lead with the first column because it is what we are built around, and for most housings it is the cheapest way to hold a thin, even wall. We also quote and manage die casting, forging and stamping, and we machine stainless steel, steel, brass, copper, titanium and engineering plastics — we will pick the column your drawing belongs in, and tell you when that is not the first one.
| Dimension | 6063 Extrusion + CNC | CNC from solid billet | Die casting |
|---|---|---|---|
| Achievable tolerance | ±0.01 mm machined, ±0.05 mm profile | ±0.01 mm, but cost rises with every feature | ±0.1 mm class accuracy |
| Minimum wall | 0.3 mm | Thin walls possible; deflection and cost become the limit | 1 mm and above |
| Material utilisation | Near-net shape; about 90% less material cut away | Low — most of the billet becomes chips | High once the die is running |
| Batch cost curve | 30–50% lower than solid billet at volume | Barely falls with volume; removal time dominates | Lowest unit cost at high volume, after die amortisation |
| Internal soundness | Wrought 6063 — dense, no porosity | Sound; no process porosity | Porosity is inherent — leak and strength risk |
| Surface and finish | Anodizes evenly; 180# bead blast without polishing | Good, but visible tool marks need finishing | Cosmetic defects need polishing before anodizing |
| Tooling and lead time | Die 4–5 days, sample about 7 days | No tooling, but slow per part | Long die lead time, high tooling cost before first good part |
| Best fit | Enclosures, heat sinks and structural housings in the 500–50,000 pcs/year range | One-offs, complex 3D geometry, low volume | Simple high-volume housings where 1 mm walls are acceptable |
Volume thresholds are indicative. We evaluate them per part: typically 500 pcs/year for large parts and 2,000 pcs/year for small parts.
Where extrusion stops working
- Cross-sections with walls below 0.3 mm — the metal will not fill consistently
- Hollow sections that need internal undercuts a die cannot release
- Parts that need a wall thicker than roughly a third of the section width without a redesign
- Very low volumes, where the die cost never amortises
Each of these has a workaround — a modified section, a machined insert or a billet-only route at low volume. We will propose one at drawing review rather than quote a part we cannot run.
Programs built on extruded profiles
Extrusion questions engineers ask
Answers to the questions that come up in almost every drawing review.
What profile tolerance can you actually hold?
±0.05 mm on the cross-section as extruded, and a wall thickness capability of ±0.02 mm on thin-wall sections. Where the assembly needs more, we machine the feature to ±0.01 mm rather than asking the die to do a machinist's job.
How thin can an extruded aluminum wall be?
0.3 mm is our minimum, achieved with a die designed for that wall and a machining sequence that does not push it. For load-bearing walls we recommend 0.6 mm and above.
Do you supply the profile only, or the finished part?
Both. Some customers take cut-to-length profiles; most take the finished housing, because the tolerance that matters is usually on a machined feature. You can also start with profiles and add machining later without changing supplier.
Can you extrude 6061 instead of 6063?
Yes. 6063-T5/T6 is our default for housings because it anodizes cleanly and takes thin walls well. 6061-T6 is stronger and machines better, but it is harder to extrude into thin sections — we will tell you which one your geometry supports.
How does extrusion compare with die casting for thin walls?
Die casting is economical at volume but carries porosity and generally needs walls of 1 mm and above. Extrusion holds 0.3 mm walls with no porosity, and CNC then tightens the critical features.
Send Your Profile Drawing. We Will Confirm the Die Before You Commit.
A section drawing or a STEP file is enough to start. You get a DFM note on wall thickness, fins and draft, plus the annual quantity at which the tooling pays back.
What to send
- 2D drawing or 3D model (STEP, IGES, DWG, DXF, PDF)
- Alloy and temper
- Surface finish and color
- Estimated annual quantity