Aluminum CNC Machining
6061, 7075, 5083 and MIC-6 parts machined to ±0.001 in, with Type II/III anodizing — from single prototypes to repeat production.
The Workhorse Material, Machined Right
CNC machining aluminum parts is the largest share of work on our floor, and for good reason: aluminum machines fast, holds tight tolerances, takes beautiful finishes, and delivers the best strength-to-weight ratio of any economical engineering metal. We run aluminum parts daily across milling, turning, and 5-axis work — from single prototypes to repeat production for North American and European OEMs. Aluminum machining services include anodizing, bead blasting, and hard coat in the same order. Whether your drawing calls for a simple 6061 bracket or a thin-walled 7075 housing, the process below is how we quote and cut it.
Aluminum Grades We Machine
- 6061-T6 — the default choice. Good strength (yield ~40 ksi / 276 MPa), excellent machinability, welds and anodizes well. Covers most brackets, housings, plates, and fixtures
- 7075-T6 — aircraft-grade strength (yield ~73 ksi / 503 MPa), nearly double 6061, at similar weight. Use where loads justify it; slightly more prone to stress corrosion and distortion on heavy pocketing
- 5083 — outstanding corrosion resistance for marine and chemical environments; softer to cut, so we watch for built-up edge
- 5052 and 6063 — sheet-adjacent and extrusion-grade alloys for formed or cosmetic parts
- 2024-T3/T4 — high fatigue strength for aerospace-style structures
- MIC-6 / cast tooling plate — stress-relieved cast plate that stays flat; the right choice for precision base plates and fixtures
Not sure between 6061 and 7075? Tell us the loads — the answer is usually 6061, and it will save you money.
Machinability and How We Cut It
Aluminum's machinability rating is roughly 3–5× that of mild steel, which is why it prices well. Our approach on the shop floor:
- High-speed cutting — carbide tooling at 800–1,500+ SFM (250–450+ m/min) with high feed rates; 2- and 3-flute polished end mills for chip evacuation
- Chip control — sharp, uncoated or ZrN-coated tools to prevent built-up edge; flood coolant or mist to keep chips from welding to the cutter
- Thin-wall strategy — symmetric roughing, reduced radial engagement, and sharp tools to control deflection and chatter on walls down to 0.020 in (0.5 mm)
- Distortion management — 7075 and heavily pocketed 6061 workpieces get balanced material removal and, where needed, stress-relief cycles between roughing and finishing. Plate-sawn stock leaves residual stress in the blank; removing material unevenly releases it and the part moves, so roughing strategy is planned before the first cut
Most aluminum work runs on CNC milling; shafts, bushings, and round parts go to the lathes, and compound-angle or contoured geometry routes to 5-axis.
Tolerances and Surface Finishes
General milled and turned features hold ±0.005 in (±0.13 mm); critical bores, datums, and mating features to ±0.001 in (±0.025 mm) quoted against the drawing. As-machined finish is Ra 3.2 µm (125 µin) standard, to Ra 0.8 µm (32 µin) on request.
Aluminum takes the widest finish range of any material we machine: Type II anodizing (clear and colors), Type III hard coat anodizing for wear surfaces, chem film (Alodine), bead blast, powder coat, nickel plating, and laser marking. Finish callouts on your drawing are quoted with the machining — see surface finishes.
Typical Aluminum Parts
Electronics enclosures and instrument housings, structural brackets, heat sinks, manifolds, drone and robotics frames, jigs and fixtures, front panels, and prototype components. Heat sinks with tall thin fins are a specialty case — fin geometry is machined, not skived, so fin thickness and spacing drive the quote.
What to Specify on the Drawing
Call out the alloy and temper explicitly (6061-T6, not just “aluminum”) — pricing and anodize response differ. Note which surfaces get anodized and whether threads should be masked; hard coat adds roughly 0.0005–0.002 in per surface, so critical bores and press fits need a masking note or an allowance. If flatness matters, say so with a value rather than leaving it to default shop tolerance, and consider MIC-6 for anything that must stay flat.
Aluminum Machining — Capability Summary
| Capability | Specification |
|---|---|
| Grades in stock | 6061-T6, 7075-T6, 5083, 5052, 6063, 2024, MIC-6 (others on request) |
| General tolerance | ±0.005 in (±0.13 mm); precision features to ±0.001 in (±0.025 mm) |
| Minimum wall thickness | 0.020 in (0.5 mm) typical, geometry-dependent |
| As-machined finish | Ra 3.2 µm (125 µin); to Ra 0.8 µm (32 µin) on request |
| Finishes | Anodizing Type II/III, chem film, bead blast, powder coat, nickel plating, laser marking |
| Batch range | 1 pc prototype to 10,000+ pcs production |
| Typical lead time | Prototypes from 3 days; production typically 2–3 weeks |
Quote Your Aluminum Parts
Send STEP files and drawings — we'll come back with pricing, lead time, and DFM feedback within 1–2 business days. For other alloys and plastics, see the full materials page.
Quote Your Aluminum Parts
Send STEP files and drawings — we'll come back with pricing, lead time, and DFM feedback within 1–2 business days.
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