COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF ALUMINIUM 2011 FASTENERS
Aluminium 2011 (UNS A92011) is globally revered in the manufacturing industry as the Free-Machining Alloy (FMA) standard for aluminium. While commercially pure grades like 1100 are incredibly soft and gummy, 2011 is heavily alloyed with 5.0% to 6.0% Copper (Cu) to massively boost its mechanical strength. More importantly, it features highly precise micro-additions of Lead (Pb) and Bismuth (Bi).
These specific heavy metal additions do not dissolve into the solid aluminium matrix; instead, they disperse as microscopic globules. When hit by a high-speed CNC cutting tool, these globules act as built-in dry lubricants and chip-breakers, causing the metal to snap into fine, powdery chips rather than long, tangled ribbons. This makes Aluminium 2011 the ultimate, undisputed choice for highly complex, custom-threaded, and precision-turned electromechanical fasteners produced on automated screw machines.
■ Product Overview & Specifications
| Material Classification | Free-Machining Copper-Aluminium Alloy |
|---|---|
| UNS Designation | A92011 |
| Microstructure | Face-Centered Cubic (FCC) with Bismuth/Lead Inclusions |
| Magnetic State | Completely Non-Magnetic |
| Density | 2.82 g/cm³ (0.102 lb/in³) |
| Size Range | Metric: M1.6 to M36 | Imperial: #0 to 1-1/2" |
| Primary Attribute | Ultimate Machinability Benchmark for Aluminium Alloys |
■ Proprietary Datasheet Download (GATED)
Aluminium 2011 Free-Machining Alloy — Complete Technical Datasheet
Contains detailed high-speed CNC spindle parameters, precise thread-cutting tolerances, and critical hard-coat anodizing guidelines to mitigate copper-induced galvanic corrosion.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
In high-speed automated manufacturing, uneven dispersion of Bismuth and Lead can cause catastrophic tool chatter and ruined threads. Ananka provides total supply-chain transparency, ensuring all 2011 solid bar stock meets stringent micro-structural uniformity standards.
- EN 10204 Type 3.1: Validates the critical 5.0–6.0% Copper inclusion for strength, verifies the exact Pb/Bi chip-breaking additions, and guarantees the T3 (solution heat-treated and cold-worked) mechanical temper.
- EN 10204 Type 3.2: Available upon request for specialized aerospace instrument housings, defense electronics, or critical pneumatic systems requiring third-party testing oversight.
■ Chemical Composition
The 2011 alloy is purposely designed for the lathe. The heavy 5% Copper addition provides the structural rigidity necessary to prevent the fastener from bending under cutting pressure, while the Bismuth and Lead intentionally create micro-fracture points within the metal to facilitate rapid, clean chip removal.
| Aluminium (Al) | Copper (Cu) | Bismuth (Bi) | Lead (Pb) | Iron (Fe) | Silicon (Si) |
|---|---|---|---|---|---|
| Balance (~92.0) | 5.0 – 6.0 | 0.20 – 0.60 | 0.20 – 0.60 | 0.70 Max | 0.40 Max |
■ Mechanical Properties
| Mechanical Property | Typical Limits (T3 Temper) |
|---|---|
| Tensile Strength | 45,000 - 55,000 psi (310 - 380 MPa) |
| Yield Strength | 38,000 - 43,000 psi (260 - 295 MPa) |
| Machinability Rating | Excellent (The Aluminium Benchmark) |
| Hardness (Brinell) | 90 - 100 HB |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| ASTM Specifications | ASTM B211 (Bar, Rod, Wire) |
| Common Trade Names | Free Machining Aluminium (FMA), Alloy 2011 |
| European Equivalent | EN AW-2011 / AlCu6BiPb |
| British Standard (BS) | FC1 |
■ Applications & Industries
- Precision Electronics: High-speed CNC machined motherboard standoffs, threaded hex spacers, and knurled thumb screws.
- Pneumatic & Fluid Power: Custom machined hose fittings, threaded valve bodies, and intricate fluid connectors requiring perfectly smooth internal threading.
- Automotive & Ordnance: Specialized carburetor parts, small high-tolerance machine screws, and clockwork mechanism components.
■ Compatible Fastener Assemblies
| Mating Machine Screws | Internal Threads (Nuts) | Washers |
|---|---|---|
| 2011 CNC Turned Screws & Studs | 2011 Custom Precision Nuts | 2024 or 6061 Aluminium Flat Washers |
■ Torque & Installation Guidelines
While 2011 possesses excellent tensile strength compared to pure aluminium, its yield point is significantly lower than standard steel. Due to the high surface quality of the machined threads, friction is low, but extreme care must be taken not to over-torque and shear the head off these precision fasteners.
| Nominal Diameter | Threads Per Inch (UNC) | Max Target Torque (in-lbs) | Max Target Torque (ft-lbs) |
|---|---|---|---|
| #8 | 32 | 18 - 22 | ~ 1.5 |
| 1/4" | 20 | 35 - 45 | ~ 3.5 |
| 3/8" | 16 | 100 - 120 | ~ 9.0 |
| 1/2" | 13 | 200 - 240 | ~ 18.0 |
■ Frequently Asked Questions
1. Can Aluminium 2011 fasteners be cold-headed like standard screws?
Absolutely not. The precise metallurgical features that make 2011 perfect for lathing—the Bismuth, Lead, and high Copper content—make it notoriously terrible for cold-forming. If you attempt to cold-head or aggressively bend a 2011 alloy rod, the micro-inclusions will act as internal stress risers, and the metal will violently crack and shatter. These fasteners are strictly manufactured via subtractive CNC machining.
2. How is the corrosion resistance of Aluminium 2011?
Poor. While pure aluminium (like 1100) is highly corrosion-resistant, the heavy 5% to 6% Copper addition in the 2011 alloy severely compromises its natural oxide layer. In humid or marine environments, internal galvanic micro-cells form between the copper and the aluminium, leading to rapid pitting. Fasteners made of 2011 should strictly be used in dry, controlled environments, or they must be hard-coat anodized to protect them.
3. Can I weld Aluminium 2011 fasteners to a frame?
No. Aluminium 2011 is generally considered unweldable. The Lead and Bismuth content will immediately boil and vaporize under the intense heat of a TIG or MIG torch, causing severe, catastrophic porosity in the weld pool and emitting highly toxic lead fumes. It is an exclusively mechanical fastening alloy.
