1100-O
Fully annealed. Lowest strength and highest ductility. Order for cold heading, upsetting, swaging, spinning and sharp bends. Standard condition for rivet stock.
Aerospace · commercially pure bar
1100 Aluminium Rod and Bar for Aerospace
1100 is the commercially pure aluminium (99.00 % min, with a little copper) that US aerospace specifications name for formable, weldable bar, rod and wire. It is used for soft "A" rivets, spun and headed fittings, bonding and earthing hardware, spacers and lightly loaded machined parts. Metline supplies 1100 rod and bar in O, H12, H14, H16, H18 and F tempers to ASTM B211, AMS-QQ-A-225/1 and AMS documents, worldwide.
- Alloy
- 1100 (UNS A91100)
- Purity
- 99.00 % Al min
- Tempers
- O, H12, H14, H16, H18, F, H112
- Standards
- ASTM B211 · AMS-QQ-A-225/1
Why aerospace drawings still call for 1100 bar
1100 is the oldest commercial aluminium grade still in everyday aerospace use. It is not strong, but it is predictable: soft, very ductile, easy to weld and braze, highly resistant to corrosion and almost impossible to crack in forming.
The alloy is 99.00 % aluminium minimum with 0.05 – 0.20 % copper. That small copper addition is what separates 1100 from 1050 and 1060: it raises strength slightly and gives a finer, more consistent grain after annealing, which helps with cold heading and spinning. Like every 1xxx alloy, 1100 cannot be heat treated for strength; all its strength comes from cold work during rolling, drawing or forming.
In aircraft work the bar form is chosen for parts that are headed, upset, spun, swaged or lightly machined. The best-known example is the rivet: in the MS/NAS rivet code, the letter "A" denotes 1100, used for non-structural riveting of soft parts such as fairings, trim and ducting where a 2117 (AD) rivet would be too hard. Other uses include electrical bonding studs and busbar pieces, spacers and bushes that must not gall softer parts, thermal conductors and heat-spreader blocks, and seal and gasket carriers.
On ground support equipment, test rigs and tooling, 1100 bar is used for formed handles, tie-down fittings and conductive components where corrosion resistance and ductility count for more than strength.
1100 chemical composition
Limits are the registered Aluminum Association values used by ASTM B211, AMS-QQ-A-225/1 and AMS bar specifications. The equivalent European grade is EN AW-1100 (Al99.0Cu).
| Element | Limit (wt %) | Comment |
|---|---|---|
| Silicon + iron (Si + Fe) | 0.95 max combined | The two main impurities are controlled together |
| Copper (Cu) | 0.05 – 0.20 | Deliberate small addition; raises strength slightly over 1050/1060 |
| Manganese (Mn) | 0.05 max | |
| Zinc (Zn) | 0.10 max | |
| Others, each / total | 0.05 / 0.15 max | |
| Aluminium (Al) | 99.00 min | By difference |
Some data sheets print silicon as 0.95 % maximum on its own. The correct limit is silicon plus iron combined.
Mechanical properties of 1100 rod and bar
The table gives typical values from published Aluminum Association and ASM data. They show the trend from fully soft O temper to full-hard H18. Specified minimums for bar and rod depend on diameter and on the specification, and are lower than typical values; design to the minimums stated on the certificate.
| Temper | Tensile strength | Yield strength (0.2 %) | Elongation (50 mm) | Brinell (500 kg) | Shear strength |
|---|---|---|---|---|---|
| O | 90 MPa / 13 ksi | 34 MPa / 5 ksi | 35 – 45 % | 23 | 62 MPa / 9 ksi |
| H12 | 110 MPa / 16 ksi | 103 MPa / 15 ksi | 12 – 25 % | 28 | 69 MPa / 10 ksi |
| H14 | 124 MPa / 18 ksi | 117 MPa / 17 ksi | 9 – 20 % | 32 | 76 MPa / 11 ksi |
| H16 | 145 MPa / 21 ksi | 138 MPa / 20 ksi | 6 – 17 % | 38 | 83 MPa / 12 ksi |
| H18 | 165 MPa / 24 ksi | 152 MPa / 22 ksi | 5 – 15 % | 44 | 90 MPa / 13 ksi |
Two practical points follow from the data. First, the yield strength of O temper is only about 34 MPa, so annealed parts deform under very modest loads; this is exactly what is wanted for a rivet shank or a crush seal, and exactly what is not wanted for a bracket. Second, cold work roughly quadruples the yield strength between O and H18, but elongation falls steeply, so hard-temper bar should not be bent sharply.
Physical properties (typical)
- Density
- 2.71 g/cm³ (0.098 lb/in³)
- Melting range
- 643 – 657 °C
- Electrical conductivity
- about 59 % IACS (O), 57 % IACS (H18)
- Thermal conductivity
- about 222 W/m·K (O)
- Thermal expansion
- 23.6 µm/m·°C (20 – 100 °C)
- Modulus of elasticity
- 69 GPa (10,000 ksi)
Which temper of 1100 bar to order
1100-H12
Quarter hard. A small increase in stiffness while keeping most of the formability; suits parts that are lightly formed and then handled.
1100-H14
Half hard. The common general-purpose condition for drawn rod, with a useful balance of strength and workability for turned parts.
1100-H16
Three-quarter hard. Higher strength where only mild forming follows.
1100-H18
Full hard, usually cold-finished rod. Highest strength and best machined finish of the 1100 tempers; limited bendability.
1100-F / H112
As fabricated (rolled or extruded). No guaranteed properties for F; H112 has minimum properties. Used for larger diameters, machining stock and parts that will be annealed later. AMS 4102 covers 1100-F bar and rod.
Standards for 1100 rod and bar
1100 is listed in more US aerospace and military documents than any other commercially pure grade. Quote the document and revision on your order; several older AMS revisions have been cancelled or stabilised, and we will confirm which revision we can certify to before you place the order.
| Document | Scope | Notes |
|---|---|---|
| ASTM B211 / B211M | Rolled, drawn and cold-finished bar, rod and wire | The general US commercial specification; also ASME SB211 |
| ASTM B221 | Extruded bar, rod, wire, profiles and tube | For extruded (H112 / F) bar |
| AMS-QQ-A-225/1 | Bar, rod and wire, 1100, rolled, drawn or cold finished | Successor to Federal QQ-A-225/1 |
| AMS 4102 | Bars and rods, rolled or cold-finished, 1100-F | Formable, weldable parts where strength is secondary |
| AMS 4180 | Wire, 1100-H18 | For wire rather than bar; see our 1100 wire page |
| EN 573-3 / EN 754 / EN 755 | Chemistry; drawn and extruded bar properties and tolerances | European route for EN AW-1100 |
| JIS H4040 | Bars and rods (A1100BD, A1100BE) | Japanese equivalent |
| System | Designation |
|---|---|
| UNS | A91100 |
| EN | EN AW-1100 / Al99.0Cu |
| ISO | Al99.0Cu |
| JIS | A1100 |
| Old British | 1200 is the closest BS grade (no copper requirement) |
How 1100 bar is made, and why it matters
The manufacturing route sets the size range, tolerance and surface you can expect. All routes start from cast billet or rolling ingot of the same chemistry.
| Route | Typical size range | Tolerance and surface | Usual tempers | Best for |
|---|---|---|---|---|
| Extruded | about 6 – 300 mm diameter | Extrusion tolerances (EN 755-9, ANSI H35.2); mill surface | F, H112, O | Machining stock, larger sizes, shapes |
| Cold drawn / cold finished | about 3 – 80 mm | Tight tolerances (EN 754-3, ASTM B211); bright surface | O, H12 – H18 | Turned parts, rivet and stud blanks |
| Rolled | Larger rounds and flats | Hot-rolled tolerances | F, O | Heavy flats and forging stock |
| Centreless ground | about 6 – 80 mm | Precision diameter and roundness to order | As supplied stock | CNC bar feeders, pins, precision bushes |
For very soft 1100-O bar, centreless grinding and long straight lengths are difficult because the bar bends under its own weight. If you need precise diameter and annealed properties, it is often better to buy cold-finished H14 or H18 bar, machine the part, and anneal the finished component.
Sizes and weights of 1100 round bar
Supply range
- Round bar
- about 3 – 300 mm, or 1/8 – 8 in cold-finished and extruded
- Square, hexagon and flat
- Drawn or extruded to section; flats for busbar and fittings
- Lengths
- 3 m, 12 ft (3.66 m), 4 m and 6 m; cut pieces to order
- Tolerances
- ASTM B211 / ANSI H35.2, or EN 754 / EN 755 class to order
- Processing
- Cut to length, chamfered ends, centreless ground on request
Weight of round bar in kg per metre is 0.002128 × d², with d in millimetres (density 2.71 g/cm³). The table covers common cold-finished inch sizes.
| Diameter (in) | Diameter (mm) | kg per metre | kg per 12 ft bar |
|---|---|---|---|
| 0.25 | 6.35 | 0.086 | 0.31 |
| 0.375 | 9.52 | 0.193 | 0.71 |
| 0.5 | 12.70 | 0.343 | 1.26 |
| 0.625 | 15.88 | 0.536 | 1.96 |
| 0.75 | 19.05 | 0.772 | 2.83 |
| 1 | 25.40 | 1.373 | 5.02 |
| 1.25 | 31.75 | 2.146 | 7.85 |
| 1.5 | 38.10 | 3.090 | 11.30 |
| 2 | 50.80 | 5.493 | 20.09 |
| 2.5 | 63.50 | 8.582 | 31.39 |
| 3 | 76.20 | 12.358 | 45.20 |
| 4 | 101.60 | 21.971 | 80.36 |
| 5 | 127.00 | 34.329 | 125.56 |
| 6 | 152.40 | 49.434 | 180.81 |
| 8 | 203.20 | 87.882 | 321.44 |
Tolerances, inspection and documents
What comes with each lot
- Chemistry
- Cast analysis on the mill certificate, checked against the specification limits
- Mechanical tests
- Tensile and yield results per lot where the specification or temper requires them
- Dimensions
- Diameter, straightness and length checked to the ordered tolerance class
- Surface
- Visual inspection for laps, seams, scratches and corrosion
- Certificate
- EN 10204 3.1, traceable to cast and lot; certificate of conformity on request
- Additional
- Third-party inspection, conductivity measurement or ultrasonic testing arranged on request
Machining, heading, welding and finishing
Machining
Machinability is fair at best: the alloy is soft and produces long, stringy chips. Use polished, very sharp carbide or HSS tools with high positive rake, high speeds, chip breakers and generous coolant. Harder tempers (H14 – H18) give a much better finish than O.
Cold heading
1100-O is one of the easiest aluminium grades to head. Heads form without cracking even with large upset ratios, which is why it is used for soft rivets and studs.
Welding
Weldable by TIG, MIG, resistance and gas methods, with 1100 or 4043 filler. Welds and the heat-affected zone return to annealed strength.
Brazing and soldering
Readily brazed with Al-Si filler metals, and solderable with suitable aluminium fluxes.
Anodising
Takes clear and dyed anodic films well, with a bright appearance.
Annealing
Full anneal at around 345 °C, hold until uniform, then air cool. Cooling rate is not critical for 1xxx alloys.
1100 compared with other bar grades
| Property | 1100-H14 | 1050A-H14 | 3003-H14 | 6061-T6 | 2011-T3 |
|---|---|---|---|---|---|
| Typical tensile | 124 MPa | ~110 MPa | 150 MPa | 310 MPa | 379 MPa |
| Heat-treatable | No | No | No | Yes | Yes |
| Machinability | Fair | Fair | Fair | Good | Excellent |
| Weldability | Excellent | Excellent | Excellent | Good | Poor |
| Corrosion resistance | Excellent | Excellent | Excellent | Good | Fair |
| Conductivity | ~57 – 59 % IACS | ~61 % IACS | ~40 % IACS | ~43 % IACS | ~39 % IACS |
If the part needs about 25 % more strength but similar forming behaviour, 3003 is the next step up. For machined fittings that carry load, 6061-T6 is the normal choice. For high-volume screw-machine parts where weldability does not matter, 2011 is much easier to machine.
How to order 1100 rod and bar
- SpecifyAlloy and temper, shape and diameter, length, quantity and the governing specification with its revision (for example ASTM B211, AMS-QQ-A-225/1 or AMS 4102).
- 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 – Standard Specification for Aluminum and Aluminum-Alloy Rolled or Cold-Finished Bar, Rod, and Wire
- SAE AMS-QQ-A-225/1 – Aluminum Alloy Bar, Rod, and Wire, Rolled, Drawn, or Cold Finished, 1100
- SAE AMS 4102 – Aluminum Alloy Bars and Rods, Rolled or Cold-Finished, 99.0Al (1100-F)
- 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
1100 aerospace aluminium (aluminum) bar: FAQ
What does the "A" in an MS or AN rivet part number mean?
In the standard rivet material code, A stands for 1100 aluminium. A rivets are soft and used only for non-structural joints in soft materials; structural rivets use 2117 (AD), 2017 (D), 2024 (DD) or 7050 (E).
Can 1100 bar be heat treated to increase strength?
No. 1100 is non-heat-treatable. Strength comes only from cold work, giving the H12 to H18 tempers. Heat treatment can only anneal it back to O.
Is 1100 aluminium good for machining?
It machines, but not easily: it is soft and gummy. Order H14 or H18 for turned parts, use sharp high-rake tools and plenty of coolant, or choose 6061 or 2011 if the design allows.
What is the difference between 1100-F and 1100-H112?
Both are as fabricated. F has no guaranteed mechanical properties; H112 has minimum properties set by the specification. Order H112 if you need any property guarantee.
What is the European equivalent of 1100?
EN AW-1100 (Al99.0Cu). The common UK grade 1200 is close but has no copper requirement and is not a direct substitute where AMS or ASTM 1100 is specified.
How much does a 1 inch 1100 round bar weigh?
About 1.37 kg per metre, or 5.0 kg for a 12 ft (3.66 m) length.
Do you ship 1100 bar internationally?
Yes. Metline supplies 1100 rod and bar worldwide from Mumbai, with mill certificates and export packing.
Need 1100 rod or bar for an aerospace part?
Send diameter, temper, length, quantity and the specification. Our team will confirm availability, certification and a delivered price.
