Aluminum 6061 CNC Machining Services
6061-T6 is the default aluminium for machined parts: predictable cutting behaviour, good strength, an excellent anodising response and the widest stock availability of any heat-treatable alloy.
6061-T6 and T651 plate, bar and billet
Tolerances to ±0.05 mm on critical features
Anodising, bead blast and chem film available
What Is Aluminum 6061?
Where 6061 fits, how it compares on cost, and how it behaves on the machine.
Aluminum 6061 is a heat-treatable aluminium-magnesium-silicon alloy, and 6061-T6 is the most widely specified aluminium grade in engineering. It delivers roughly two thirds of the tensile strength of 7075-T6 at a fraction of the material cost, welds without special procedure, and takes an anodised finish that stays colour-consistent across a production batch.
Why engineers default to 6061
The alloy pairs a 310 MPa ultimate tensile strength with 12 percent elongation, so it carries load without brittle failure, and it cuts cleanly at high spindle speeds with short, manageable chips. It is stocked in every product form: plate, bar, tube, extrusion and billet. That availability is what keeps lead times short when a design changes late in the programme.
Tempers and forms we machine
6061-T651 plate and bar are the usual starting condition because the stretching operation relieves internal stress, which limits distortion when you remove a large volume of material. 6061-O and 6061-T4 are used where the part must be formed before machining and then aged to T6. State the required temper on the drawing; we machine to the specified condition and can supply material certification to EN 10204 3.1.
Related capabilities: CNC Machining, CNC Milling, CNC Turning, 5-Axis Machining. Dimensional limits, thread rules and surface roughness grades are listed on the tolerances and specifications page, and volume-based routing is covered under production solutions.
Aluminum 6061 Mechanical Properties
Typical values at room temperature for the condition most often machined. Use them for material screening, then confirm against the mill certificate for the exact heat and product form.
| Property | Typical value |
|---|---|
| Density | 2.70 g/cm³ |
| Ultimate tensile strength | 310 MPa (45 ksi) |
| Tensile yield strength, 0.2% offset | 276 MPa (40 ksi) |
| Elongation at break | 12% in 50 mm |
| Elastic modulus | 68.9 GPa |
| Brinell hardness | 95 HB |
| Shear strength | 207 MPa |
| Fatigue strength | 96.5 MPa |
| Thermal conductivity | 167 W/m·K |
| Melting range | 582 to 652 °C |
Typical room-temperature values compiled from public ASM, MatWeb and mill datasheets. Actual values vary with temper, section thickness and product form; request the EN 10204 3.1 certificate for critical applications.
Machining Characteristics of Aluminum 6061
How the material behaves in the cut, and what that means for tooling, fixtures, cycle time and achievable tolerance.
Predictable cutting
The T6 temper produces short chips and low built-up edge, so surface finish and tool life stay stable at high spindle speeds with standard carbide tooling.
Thin-wall behaviour
Stiffer than pure aluminium, but walls under 1 mm still need balanced stock removal, sharp tooling and a light finishing pass to hold flatness.
Threads and tapping
Cut and formed threads both work. Roll-formed threads in T6 give better fatigue life for features that are assembled repeatedly.
Welding around machined features
6061 welds readily with 4043 or 5356 filler. The heat-affected zone locally loses T6 properties, so critical faces are usually machined after welding.
Anodising response
Type II and Type III hardcoat anodising build uniform, cosmetic-quality oxide layers on 6061, which is why the alloy dominates enclosures and consumer hardware.
Thermal drift
With 167 W/m·K conductivity the part heats and cools quickly. Dimensional checks on tight features are made at 20 °C to avoid false rejects.
Design and Machining Checklist
Practical rules that reduce cost and scrap on Aluminum 6061 parts. Share them with your design team before the drawing is frozen.
- Keep wall thickness at or above 0.8 mm for aluminium parts, and above 1.5 mm where the wall is taller than 25 mm.
- Use an internal corner radius of at least one third of the cavity depth so a standard end mill can reach the floor.
- Apply tight tolerances only where function demands it; ISO 2768-m covers most non-critical features and costs far less to produce.
- Allow for anodising build-up of roughly 5 to 25 µm per surface on threads, bores and mating faces.
- Break all sharp edges before anodising, otherwise current density spikes cause burning on corners.
- Avoid large uninterrupted flat faces that must stay flat; ribbing or shallow pockets keep the part stable.
Surface Finishing Options
Finishes are selected for corrosion resistance, wear, appearance, electrical behaviour or cleanliness. Specify only what the function needs.
As-Machined
Ra 1.6 to 3.2 µm with visible tool marks. The fastest route and the default for internal or non-visible surfaces.
Bead Blasting
Uniform matte texture that hides tool marks and handling scratches, typically Ra 1.6 to 3.2 µm before anodising.
Type II Anodising
5 to 25 µm decorative and corrosion-resistant oxide. Available clear, black, red, blue and gold, and it can be dyed before sealing.
Type III Hardcoat
25 to 75 µm wear-resistant oxide for sliding, abrasive or high-cycle contact surfaces. Slight dimensional growth must be allowed for.
Chemical Conversion Coating
Chromate or non-chrome film that keeps electrical conductivity while adding corrosion protection and a paint key.
Powder Coating
60 to 120 µm polymer layer in almost any colour, with far better impact and UV resistance than wet paint.
Typical Applications
Where Aluminum 6061 is most often specified, and why it wins against the alternatives.
Aerospace brackets and fittings
Structural brackets, seat hardware and instrument mounts where strength-to-weight and traceability both matter.
Automotive and motorsport
Suspension adapters, mounting plates, manifold spacers and lightweight brackets for race and road programmes.
Robotics and automation
Machine frames, motor mounts, end-effector plates and sensor brackets that must stay flat under bolted load.
Electronics enclosures and heat sinks
Housings and finned heat sinks that exploit 167 W/m·K conductivity and take a clean anodised finish.
Marine hardware
Deck fittings, cleats and instrument housings, usually hardcoat anodised or powder coated for salt spray resistance.
Jigs, fixtures and tooling plate
Cast and ground tooling plate for welding fixtures, inspection jigs and assembly aids in the factory.
Need Aluminum 6061 parts quoted?
Upload your CAD files for a detailed quote on Aluminum 6061 components, including material certification, finishing, inspection and worldwide delivery.