Maximum productivity, protected environment
2011-T3 or a lead-free 2xxx substitute: screw-machine parts, fittings and inserts that are plated, painted or used indoors.
Machining materials guide
Free-Cutting Aluminium Bar
Free-cutting aluminium bar contains small additions of low-melting elements such as lead, bismuth or tin that make chips break into short curls instead of long strings. That lets automatic lathes and CNC machines run faster, unattended, with better surface finish. This guide compares the classic grades (2011, 2007, 6262) with the newer lead-free grades (6026, 6023, 6262A and others), and explains how to choose between them.
- Grades
- 2011, 2007, 2030, 6262, 6026
- Lead-free
- 6026, 6023, 6262A, 6065
- Diameter
- about 4 – 400 mm
- Standards
- ASTM B211 · EN 754 / 755
What makes an aluminium bar free-cutting?
Standard aluminium alloys such as 6061 or 6082 are ductile, so when turned they tend to form long, continuous chips. On a multi-spindle or Swiss-type lathe those chips wrap around tools and parts, scratch surfaces and force the machine to stop. Free-cutting alloys solve this metallurgically.
Elements that are almost insoluble in aluminium, traditionally lead and bismuth, form tiny separate particles in the metal. During cutting, heat at the tool tip softens or melts these particles and the chip breaks at each one. The result is short, easily cleared chips, lower cutting forces and less built-up edge on the tool. Tin is now used as a lead substitute in many grades, alone or with bismuth.
Because lead is restricted under the EU RoHS and End-of-Life Vehicles (ELV) directives, the market has moved steadily toward lead-free free-cutting grades. These achieve similar chip breaking while meeting the much lower lead limits demanded by automotive and electronics customers.
Common free-cutting aluminium grades
| Alloy | Family | Chip-breaking additions | Key characteristics |
|---|---|---|---|
| 2011 | Al-Cu | Pb and Bi | The benchmark for machinability; high strength, poor corrosion resistance and poor anodising |
| 2007 / 2030 | Al-Cu-Mg | Pb | European high-strength free-machining grades; machine very well, limited corrosion resistance |
| 6262 | Al-Mg-Si | Pb and Bi | Like 6061 with free-cutting additions; good corrosion resistance and anodising |
| 6262A | Al-Mg-Si | Bi and Sn (lead-free) | Lead-free counterpart to 6262 |
| 6026 | Al-Mg-Si | Bi (low-lead versions available) | Widely used lead-free substitute for 6262 and 2011 in many parts |
| 6023 | Al-Mg-Si | Bi and Sn | Lead-free, good machinability and anodising |
| 6020 | Al-Mg-Si | Sn | Lead-free; lower impact toughness |
| 6065 | Al-Mg-Si | Bi (Pb ≤ 0.05 %) | Lead-free alternative to 6262 with similar properties |
Lead-free bismuth-based 2xxx grades are also offered as replacements for 2011. Confirm the exact registered composition and the lead limit your customer requires before ordering.
Chemical composition of key grades (wt %)
Values are registered limits (Aluminum Association / EN 573-3) for the main and chip-breaking elements; single figures are maximums. The mill certificate for each lot reports the actual analysis.
| Alloy | Si | Cu | Mn | Mg | Pb | Bi | Sn |
|---|---|---|---|---|---|---|---|
| 2011 | 0.40 | 5.0 – 6.0 | — | — | 0.20 – 0.6 | 0.20 – 0.6 | — |
| 2007 | 0.8 | 3.3 – 4.6 | 0.50 – 1.0 | 0.40 – 1.8 | 0.8 – 1.5 | 0.20 | 0.20 |
| 2030 | 0.8 | 3.3 – 4.5 | 0.20 – 1.0 | 0.50 – 1.3 | 0.8 – 1.5 | 0.20 | — |
| 6262 | 0.40 – 0.8 | 0.15 – 0.40 | 0.15 | 0.8 – 1.2 | 0.40 – 0.7 | 0.40 – 0.7 | — |
| 6262A | 0.40 – 0.8 | 0.15 – 0.40 | 0.15 | 0.8 – 1.2 | low | 0.40 – 0.9 | 0.40 – 1.0 |
| 6026 | 0.6 – 1.4 | 0.20 – 0.50 | 0.20 – 1.0 | 0.6 – 1.2 | 0.40 | 0.50 – 1.5 | 0.05 |
| 6023 | 0.6 – 1.4 | 0.20 – 0.50 | 0.20 – 0.6 | 0.4 – 0.9 | low | 0.30 – 0.8 | 0.6 – 1.2 |
| 6065 | 0.40 – 0.8 | 0.15 – 0.40 | 0.15 | 0.8 – 1.2 | 0.05 | 0.50 – 1.5 | — |
Typical mechanical properties
Typical values below are published figures for the most common tempers. Specified minimums depend on the standard, product form (drawn or extruded) and diameter, and are stated on the certificate. For EN grades such as 2007, 2030, 6026 and 6023, design to the minimums in EN 754-2 or EN 755-2 for your diameter.
| Alloy and temper | Tensile strength | Yield strength | Elongation | Machinability |
|---|---|---|---|---|
| 2011-T3 (typical) | 379 MPa | 296 MPa | 15 % | Excellent (benchmark) |
| 2011-T8 (typical) | 407 MPa | 310 MPa | 12 % | Excellent |
| 6262-T6 (typical) | 290 MPa | 240 MPa | 12 % | Very good |
| 6262-T9 (typical) | 400 MPa | 380 MPa | 10 % | Very good |
| 6061-T6 (for comparison) | 310 MPa | 276 MPa | 12 % | Good, but long chips |
2011 has the best chip breaking but its high copper content gives poor resistance to corrosion and a dull, uneven anodised finish. 6xxx free-cutting grades sacrifice a little machinability for much better corrosion resistance and decorative or hard anodising, which is why they dominate in hydraulics, pneumatics and visible parts.
How to choose a free-cutting grade
Anodised or corrosion-exposed parts
6262, 6026 or 6023: hydraulic and pneumatic valve bodies, brake and transmission components, camera and optical parts.
High strength
2007, 2030 or 2011-T8 for highly stressed small parts; 6262-T9 where 6xxx corrosion resistance is also needed.
RoHS / ELV lead limits
Choose a lead-free grade such as 6026, 6023, 6262A or 6065 and specify the maximum lead content on the order.
Welding required
Avoid free-cutting alloys: the low-melting additions cause hot cracking. Use 6061 or 6082 for welded parts.
Cold heading or forming
Free-cutting grades have reduced cold formability; check bend and crimp operations before switching.
Lead restrictions: RoHS and ELV
Under the EU RoHS Directive (2011/65/EU) the general limit for lead in homogeneous materials is 0.1 %. Annex III exemption 6(b) has allowed limited lead in aluminium alloys, including for machining purposes up to 0.4 %, and the ELV Directive (2000/53/EC) contains a similar exemption for vehicles. These exemptions have been progressively narrowed and are periodically reviewed.
- Check the current Annex III (RoHS) and Annex II (ELV) wording and expiry dates for your product category before choosing an alloy
- State the maximum lead content on the purchase order, for example "Pb ≤ 0.1 %", rather than relying on the alloy name alone
- Ask for lead to be reported on the mill certificate for every lot
- Remember that recycled aluminium can carry trace lead, so specify limits even for nominally lead-free grades
- Customers outside the EU often follow the same limits through their own regulations or through supply-chain requirements
Machining free-cutting aluminium bar
- ToolingUse sharp, polished carbide or PCD inserts with high positive rake and large chip gullets. Uncoated or DLC-coated grades resist built-up edge.
- Speeds and feedsRun high spindle speeds; feed heavily enough to form a proper chip. Very light feeds can rub rather than cut, even with free-cutting stock.
- CoolantFlood emulsion or neat oil keeps the tool cool and flushes chips; on 6xxx lead-free grades good coolant helps chip breaking further.
- Bar straightnessHigh-speed bar feeders need straight bar to avoid vibration. Agree straightness and surface condition for automatic-lathe work.
- Finishing6xxx grades anodise well, including hard anodising; 2011 is better plated or painted. Bismuth- and tin-bearing grades may show slight colour differences after anodising, so run a sample.
Supply range and standards
Free-cutting bar supply
- Grades
- 2011, 2007, 2030, 6262, 6262A, 6026, 6023, 6020, 6065 and lead-free 2xxx grades
- Tempers
- T3, T4, T451, T6, T651, T6511, T8, T9 by grade
- Shapes
- Round, hexagon, square and flat bar
- Diameter
- About 4 – 400 mm, drawn sizes for small diameters, extruded for large
- Length
- Typically 2.5 – 6 m random or fixed lengths; cut pieces on request
- Standards
- ASTM B211 (cold finished), ASTM B221 (extruded), EN 754 (drawn), EN 755 (extruded), EN 573-3 (chemistry)
- Tolerances
- Drawn bar to h9 – h11 class tolerances typical for automatic lathes; extruded bar to EN 755 or ASTM tolerances
- Certification
- EN 10204 3.1 mill test certificate including lead, bismuth and tin
Bar weight: 6xxx bar weighs about 2.70 g/cm³ and 2xxx copper-bearing grades about 2.8 – 2.85 g/cm³. A round bar weighs π × r² × length × density, so a 30 mm × 3 m round bar in 6026 weighs about 5.7 kg, and the same bar in 2011 (2.83 g/cm³) about 6.0 kg.
References and standards
- ASTM B211/B211M – Aluminum and Aluminum-Alloy Rolled or Cold-Finished Bar, Rod and Wire
- EN 573-3 – Chemical composition and form of wrought aluminium products
- EN 754-2 and EN 755-2 – Cold drawn and extruded rod/bar: mechanical properties
- Directive 2011/65/EU (RoHS) – Annex III exemptions
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
- ASM Handbook, Vol. 2 – Properties of Wrought Aluminum Alloys
Free-cutting aluminium (aluminum) bar: FAQ
What is the most machinable aluminium alloy?
2011 is the traditional benchmark, producing fine broken chips and excellent finish. Its weakness is corrosion resistance and anodising, so 6262 and lead-free 6026 or 6023 are preferred for exposed or anodised parts.
Is 2011 aluminium RoHS compliant?
Standard 2011 contains 0.20 – 0.6 % lead, above the 0.1 % general RoHS limit, so compliance depends on exemption status. For RoHS or ELV-sensitive parts choose a lead-free grade and specify maximum lead on the order.
What is the difference between 6262 and 6026?
Both are Al-Mg-Si free-cutting alloys. 6262 uses lead and bismuth; 6026 relies on bismuth and is available in low-lead versions, making it a common lead-free substitute with similar strength and good anodising.
Can free-cutting aluminium be welded?
Not recommended. Lead, bismuth and tin form low-melting phases that cause hot cracking. Use 6061 or 6082 for welded parts.
Can free-cutting aluminum bar be anodised?
6xxx free-cutting grades anodise well, including hard anodising. 2011 and other high-copper grades give a dull, uneven anodic layer and are usually plated or painted.
What sizes can Metline supply?
Round, hexagon, square and flat free-cutting bar from about 4 to 400 mm, drawn or extruded, cut to length if needed, with EN 10204 3.1 certificates and export packing worldwide.
Switching to lead-free free-cutting bar?
Send your current grade, sizes, tolerances and lead limit. We will suggest a matching grade and quote with certification.
