Lead-free 2xxx
Alloys such as 2033 replace lead with bismuth and tin and keep machinability close to 2011.
Aerospace · free-machining bar
2011 Aluminium Bar and Rod for Aerospace
2011 is the free-machining aluminium alloy: copper for strength, plus lead and bismuth that break chips into tiny fragments. It is used for high-volume screw-machine parts such as fittings, inserts, spacers, nuts and instrument components. Metline supplies 2011 round, hex and square bar in T3, T4/T451 and T8 to ASTM B211 and AMS-QQ-A-225/3, with mill certificates, worldwide.
- Alloy
- 2011 (AlCu6BiPb)
- Tempers
- T3, T4/T451, T8
- Diameter
- about 3 – 200 mm
- Standards
- ASTM B211 · AMS-QQ-A-225/3
Why 2011 is used for machined parts
2011 is rated as the benchmark for aluminium machinability. Fine, insoluble particles of lead and bismuth soften locally as the tool passes, so chips break into small pieces instead of long strings. That keeps automatic lathes running unattended and gives an excellent surface finish.
In aerospace and defence supply chains, 2011 bar is used for parts made in large numbers on automatic and CNC lathes where the material is not the primary structure: hydraulic and pneumatic fittings for low-stress service, threaded inserts and bushes, spacers, nuts, instrument and avionics hardware, connector bodies and camera or sensor parts. Its strength in T3 is comparable to 6061-T6 or better.
The compromises are corrosion resistance and weldability. The high copper content makes 2011 more prone to corrosion than 6xxx alloys, so parts are usually anodised or coated, and it is not considered weldable by fusion processes. It is also not suitable for fatigue-critical structure.
2011 chemical composition (wt %)
| Element | Limit | Role |
|---|---|---|
| Copper (Cu) | 5.0 – 6.0 | Strength through heat treatment |
| Lead (Pb) | 0.20 – 0.6 | Chip breaking |
| Bismuth (Bi) | 0.20 – 0.6 | Chip breaking; offsets lead's effect on hot shortness |
| Silicon (Si) | 0.40 max | Impurity |
| Iron (Fe) | 0.7 max | Impurity |
| Zinc (Zn) | 0.30 max | |
| Others, each / total | 0.05 / 0.15 max | |
| Aluminium (Al) | Remainder |
Silicon is a maximum of 0.40 %, not a 0.40 – 0.80 % range as some data sheets show.
Mechanical properties of 2011 bar
| Temper | Tensile (typical) | Yield (typical) | Elongation | Brinell | Conductivity |
|---|---|---|---|---|---|
| T3 | 379 MPa / 55 ksi | 296 MPa / 43 ksi | 15 % | 95 | about 39 % IACS |
| T8 | 407 MPa / 59 ksi | 310 MPa / 45 ksi | 12 % | 100 | about 45 % IACS |
Specified minimums are lower and depend on diameter: for small-diameter T3 rod, ASTM B211 minimums are around 310 MPa (45 ksi) tensile and 262 MPa (38 ksi) yield, falling for larger diameters. T8 (solution treated, cold worked and artificially aged) gives higher strength and better resistance to stress-corrosion cracking than T3, and is preferred where parts are exposed. Design to the minimums on the certificate.
Physical properties (typical)
- Density
- 2.83 g/cm³
- Melting range
- about 540 – 643 °C
- Thermal conductivity
- about 150 – 170 W/m·K by temper
- Modulus of elasticity
- about 70 GPa
Standards and equivalents
| Document / system | Designation or scope |
|---|---|
| ASTM B211 / B211M | Rolled or cold-finished bar, rod and wire: 2011-T3, T4, T451, T8 |
| AMS-QQ-A-225/3 | Bar, rod and wire, 2011, rolled, drawn or cold finished |
| EN 573-3 / EN 754-2 | EN AW-2011 (AlCu6BiPb), drawn bar; T3, T6 and T8 listed in European practice |
| UNS / Werkstoff | A92011 / 3.1655 |
| JIS | A2011 |
AMS 4115 and AMS 4116 appear on some 2011 data sheets, but both are 6061 bar specifications and do not cover 2011.
Lead content and lead-free alternatives
Because 2011 contains up to 0.6 % lead, it falls under lead restrictions in regulations such as the EU RoHS and End-of-Life Vehicles directives, which allow lead in aluminium only within exemption limits that are periodically reviewed. Aerospace equipment is often outside the scope of these rules, but many programmes and their customers now ask for lead-free material anyway.
Lead-free 6xxx
6026 and 6262-type grades offer good machining with much better corrosion resistance and anodising response.
6061-T6
Machines well with good chip control on modern tooling, and is weldable; the default when machining speed is less critical.
Machining, finishing and joining
- Machining: high speeds with sharp carbide or HSS tools; small broken chips and excellent finish without chip breakers
- Anodising: possible, but the copper content gives a duller, less uniform film than 6xxx alloys; hard anodising is limited
- Welding: not recommended by fusion welding; join mechanically
- Corrosion: fair; protect parts by anodising, conversion coating or painting, and prefer T8 for exposed service
How to order 2011 bar
- SpecifyAlloy and temper, shape, diameter or across-flats, length, quantity and the governing specification with its revision (ASTM B211, AMS-QQ-A-225/3 or EN 754-2).
- ConfirmWe confirm the specification can be met, the tolerance class, test requirements and delivery terms (EXW, FOB, CIF or DAP).
- InspectMaterial is checked for dimensions and surface condition; any extra tests named on the order are carried out or arranged.
- DocumentEach lot ships with a mill test certificate to EN 10204 3.1 showing chemistry and mechanical results, traceable to the heat or lot number.
- Pack and shipExport packing in sealed, moisture-protected cases or on pallets, shipped by sea or air to your port or door.
References and standards
- ASTM B211 – Aluminum and Aluminum-Alloy Rolled or Cold-Finished Bar, Rod, and Wire
- SAE AMS-QQ-A-225/3 – Aluminum Alloy Bar, Rod, and Wire, Rolled, Drawn, or Cold Finished, 2011
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
2011 aluminium (aluminum) bar: FAQ
Is 2011-T6 a standard temper?
ASTM B211 lists 2011 in T3, T4, T451 and T8. T6 appears in some European listings. For US aerospace orders, T3 or T8 is normal.
Which is better, 2011-T3 or T8?
T8 is slightly stronger and more resistant to stress-corrosion cracking; T3 is the most common stock temper. Choose T8 for exposed parts.
Can 2011 be welded?
It is not recommended for fusion welding. Join 2011 parts mechanically.
Does 2011 contain lead?
Yes, 0.20 – 0.6 % lead plus a similar amount of bismuth. Lead-free alternatives such as 2033 or 6026 are available where required.
Which AMS specification covers 2011 bar?
AMS-QQ-A-225/3. AMS 4115 and AMS 4116 are 6061 specifications and do not apply.
Need 2011 bar for screw-machine parts?
Send the shape, diameter, temper, length and specification. We reply with availability and a delivered price.
