1100 aluminum alloy is the default choice when a part has to form easily, conduct well and resist corrosion, and does not have to carry load. It is 99.0% aluminium minimum, with a small copper addition that lifts strength a little above the purer 1050 and 1060 without turning it into a structural alloy.
That single copper addition explains most of what follows. It is also why 1100 sits where it does in the 1xxx family: more strength than 1050, slightly less conductivity, slightly less corrosion margin, and a lower cost than the heat-treatable grades.
What Is 1100 Aluminum?
1100 is a wrought, commercially pure aluminium alloy in the 1xxx series, registered by the Aluminum Association and supplied under UNS A91100. European standards know it as EN AW-1100, chemical designation Al99.0Cu; Japanese standards as A1100P for sheet. The “commercially pure” label is precise: this is not 99.99% metal, but aluminium with a controlled ceiling on impurities and one deliberate alloying addition.
The grade is não tratável termicamente. There is no solution treatment and no aging step, so its strength comes only from cold work. That is why you order 1100 by temper — O, H12, H14, H16, H18 — and why a request for “1100-T6” cannot be filled: no such temper exists in this alloy. If a drawing specifies one, the drawing is wrong and should be corrected before the order is placed, not after.
Product forms and their governing standards:
| Formulário | Padrão |
|---|---|
| Chapa e placa | ASTM B209 / ASME SB-209 |
| Bar, rod and wire | ASTM B211 |
| Extruded shapes and tube | ASTM B221 |
| Drawn tube | ASTM B234 |
| Aerospace sheet (O, H14) | AMS 4001, AMS 4003 |
Composição química
The limits below are the registered composition for 1100. Iron and silicon are residuals from smelting rather than additions, which is why they are capped as a combined figure.
| Elemento | Limit (wt%) | Função |
|---|---|---|
| Alumínio | 99.00 min | Metal base |
| Si + Fe | 0.95 max | Residuals from smelting; raise strength, lower conductivity |
| Cu | 0.05–0.20 | The only deliberate addition; raises strength |
| Mn | 0,05 máximo | Residual |
| Zn | 0,10 máximo | Residual |
| Outros, cada | 0,05 máximo | Residual |
| Outros, total | 0,15 máximo | Residual |
Copper is the element to watch on a certificate. At the low end of the 0.05–0.20% window, 1100 behaves almost like 1050. At the high end it is measurably stronger and slightly less conductive. Both ends are within specification, so a mill certificate that shows copper without showing where in the window the heat fell tells you less than it appears to.
Propriedades mecânicas e físicas
Propriedades por Têmpera
Because 1100 hardens only by cold work, temper is the whole strength story. The figures below are typical values for sheet; the guaranteed minimums in ASTM B209 sit below them and vary with thickness, so read the standard for the gauge you are buying.
| Temperamento | Resistência à tração (MPa) | Limite de escoamento (MPa) | Alongamento (%) |
|---|---|---|---|
| O (recozido) | ~90 | ~35 | ~35 |
| H12 (quarto duro) | ~110 | ~100 | ~12 |
| H14 (meio duro) | ~125 | ~115 | ~9 |
| H16 (três quartos duro) | ~145 | ~138 | ~6 |
| H18 (duro total) | ~165 | ~152 | ~5 |
Two things stand out. First, the gap between yield and tensile closes sharply as cold work rises — annealed 1100 yields at roughly 39% of its tensile strength, while H18 yields at about 92%. A part that was designed around annealed behaviour and then switched to H18 has almost no reserve before it yields. Second, elongation falls from about 35% to about 5% across the ladder, which is the real reason you cannot deep-draw H18 stock.
Propriedades físicas
| Propriedade | Valor |
|---|---|
| Densidade | 2,71 g/cm³ |
| Faixa de fusão | 643–657 °C |
| Thermal conductivity (O, 20 °C) | ~222 W/(m·K) |
| Electrical conductivity (O, 20 °C) | 59% IACS |
| Coeficiente de expansão térmica (20–100 °C) | 23.6 µm/(m·K) |
| Módulo de Young | 69 GPa |
| Coeficiente de Poisson | 0.33 |
The 59% IACS figure is quoted in the annealed condition, which is the state conductivity tables normally report. Cold working moves it down slightly, so an H18 part will not match an O-temper datasheet number. This matters when a specification is written around a minimum conductivity: state the temper alongside the percentage, or the requirement cannot be verified against the certificate.
For context, dedicated electrical conductor grade 1350 guarantees 61.5% IACS minimum. 1100 sits two points below it, and that gap is the reason overhead line and magnet wire work goes to 1350 rather than 1100.
Tempers and Forms Available
1100 is supplied across the full strain-hardened range: O, H12, H14, H16 and H18, plus the H22, H24, H26 and H28 variants. The H2x tempers are strain-hardened to the same strength band as their H1x equivalents and then partially annealed, which buys back some ductility at the same nominal strength. For extruded and forged product there is also H111 and H112, the tempers used where the part gets some work after forming and properties are not tightly specified.
Form availability drives more specification errors than temper does:
- Bobina and sheet — the volume product, from thin gauge up to plate; fin stock and deep-drawn parts come from here.
- Placa — heavier sections, often H112; used for tanks, jigs and machined blanks.
- Bar, rod and wire — rivet stock, welding wire feed, decorative and electrical wire.
- Tube and profile — 1100 extrudes readily, so tube and simple profiles are available, though 6063 is the usual choice where strength or surface finish matters more. Alloy choice does not change stiffness — every aluminium alloy sits at about 69 GPa — so rigidity comes from section geometry.
One limit is worth stating plainly: 1100 is a foil alloy, but not the foil grade for thin food wrap. Wrap and container foil in the 6–20 µm range is normally 1235, 8079 or 8011, chosen for purity, pinhole resistance and cost. 1100 shows up in fin stock and heavier gauge foil, where its strength and formability are worth more than the last point of purity.
Where 1100 Aluminum Is Used
The applications below all share one condition: the part has to form, conduct or resist corrosion, and it does not have to carry significant load.
Heat transfer. Fin stock, heat exchanger fins, radiator cores and cooling fins. The combination of ~222 W/(m·K) thermal conductivity, 2.71 g/cm³ density and enough strength to survive fin forming is hard to match at the price.
Chemical and food processing. Storage tanks, process vessels, piping and handling equipment. 1100 resists atmospheric and water corrosion and a wide range of chemicals, and it welds without fuss, which is what process equipment fabrication actually needs. Strong alkalis are the exception and should be checked against the service medium.
Sheet metal work and spun parts. Hollowware, cookware, utensils, lamp housings and drawn components. The slow work-hardening rate lets a part go through several forming stages without an intermediate anneal, which is the single biggest cost advantage of this grade on a press.
Reflectors, nameplates and trim. 1100 takes a high polish, anodises to a clear finish and holds reflective performance; it is a common substrate for lighting reflectors, dials and decorative trim.
Electrical hardware. Busbar, connectors, shielding and general conductor work where 59% IACS is sufficient. Overhead transmission and magnet wire are a different job: those specifications call for 1350 at 61.5% IACS minimum, and substituting 1100 changes the current rating.
Rebites e fixadores. Low strength, high ductility and good corrosion resistance make 1100 a natural rivet alloy where the joint is not highly loaded.
1100 vs 1050, 1060, 3003 and 5052
The differences below come from composition, not from processing, so they do not narrow with temper choice.
| Propriedade | 1100 | 1050 | 1060 | 3003 | 5052 |
|---|---|---|---|---|---|
| Aluminium content | 99.0% min + Cu | 99,5% mín. | 99,6% mín. | Bal. + 1.0–1.5% Mn | Bal. + 2.2–2.8% Mg |
| Tensile strength, O (MPa) | ~90 | ~75 | ~70 | ~110 | ~195 |
| Yield strength, O (MPa) | ~35 | ~30 | ~25 | ~40 | ~90 |
| Elongation, O (%) | ~35 | ~40 | ~40 | ~30 | ~25 |
| Condutividade elétrica (% IACS) | 59 | ~61 | 61–62 | 44–50 | ~35 |
| Thermal conductivity (W/(m·K)) | ~222 | ~230 | ~234 | ~190 | ~138 |
| Resistência à corrosão | Excelente | Excelente | Excelente | Muito boa | Excellent, incl. marine |
| Anodising response | Good, slight grey from Cu | Excellent, bright | Excellent, bright | Good, slightly grey | Bom |
| Usinabilidade | Poor, gummy | Poor, gummy | Poor, gummy | Justo | Justo |
Contra 1050 and 1060 the difference is purity. Dropping from 99.5% to 99.0% aluminium and adding copper buys roughly 15 MPa of tensile strength at the cost of about two points of conductivity and a slightly duller anodised finish. Where the specification is written around maximum conductivity or a bright anodic film, the purer grades win; where it is written around cost and forming, 1100 usually does.
Contra 3003 the difference is manganese. The 1.0–1.5% manganese in 3003 raises annealed yield strength only modestly — about 40 MPa against 35 for 1100 — but it extends how far the alloy work-hardens, and that is where the real gap opens: in the half-hard temper 3003 typically yields around 145 MPa against about 115 MPa for 1100. The cost is conductivity, which falls into the 44–50% band.
Contra 5052 the difference is magnesium. At 2.2–2.8% magnesium, 5052 yields at roughly 90 MPa in the annealed condition — about two and a half times 1100 — and reaches around 190 MPa in H32, while performing in salt water at about a third of the conductivity. These two rarely compete for the same part; the choice is usually decided before the alloy is named.
Working With 1100
Formabilidade
Annealed 1100 is among the most formable of the common wrought alloys — the purer 1050 and 1060 edge it slightly, but 1100 is the cheaper route to the same behaviour. It deep-draws, spins, stamps and bends to tight radii, and because it work-hardens slowly it tolerates multi-stage forming that would crack a harder temper. Design around the O temper for severe forming: if the finished part has to carry H14 properties in service, that decision belongs before forming, not after.
Springback is low but not zero, and it rises sharply with temper. Tooling proven on O temper will not produce the same angle on H14 without compensation.
Soldadura e ligação
1100 welds with all conventional processes: TIG (GTAW), MIG (GMAW), resistance and flash welding, plus brazing and soldering, where its low melting range and high fluidity make it one of the easier alloys to join.
Filler choice is a real decision rather than a formality:
- ER1100 matches the base metal, giving the best conductivity and corrosion behaviour, with lower as-welded strength.
- ER4043 (Al-5Si) gives higher as-welded strength and better crack resistance but reduces conductivity in the weld zone.
Neither choice restores strength by heat treatment afterwards, because the alloy does not respond to it. Design the joint for the annealed condition in the heat-affected zone, not for the temper of the parent metal.
Usinagem
This is 1100’s weakest property. The alloy is soft and gummy: it forms a built-up edge, refuses to break a chip cleanly and produces a poor surface if the tool rubs instead of cuts.
What works: sharp, high-rake carbide or high-speed steel, generous rake angles, constant feed to keep the tool under the work rather than sliding on it, and flood coolant. What does not work: taking a light finishing pass with a dull tool. For high-volume machined parts, 2011 or 6262 will cost less per part than fighting 1100.
Anodising and Surface Finish
1100 anodises cleanly in sulphuric acid and takes dye well, but the copper content greys the film slightly compared with 1050. Where colour match across parts matters, that difference is visible. Polishing, brushing, powder coating and PVC film protection all apply normally, and hard anodising is possible, though wear performance is limited by the soft substrate underneath.
Go / No-Go: When 1100 Is the Right Call
Go when the requirement is:
- Severe forming — deep draws, multi-stage press work, spinning — and the load on the finished part is light.
- Thermal duty — fin stock, heat exchangers, heat sinks — where conductivity earns more than strength.
- Electrical hardware at 59% IACS — busbar, connectors, shielding — but not overhead line or magnet wire.
- Chemical or food process equipment that has to weld easily and resist attack, with no pressure duty.
- Reflectors, nameplates, trim and decorative work that needs a polishable, anodisable, low-cost substrate.
No-Go when:
- The part carries structural load. 3003 and 5052 both keep far more strength after work hardening, and that gap does not close by ordering a harder 1100 temper.
- Service is marine and load-bearing. 1100 resists salt atmosphere but not as a structural marine alloy.
- Service temperature climbs much above 150 °C. The cold work that provides the strength begins to anneal out, and there is no precipitation hardening to take over.
- The part is machined in volume. Gummy chips and built-up edge make 1100 a poor machining alloy regardless of tooling.
- The specification says 1100-T6. That temper does not exist; the requirement has to be re-expressed as a temper plus a strength minimum.
- Thin food-wrap foil is the product. 1235, 8079 and 8011 are the foil grades.
Conclusão
1100 trades strength for formability, conductivity and corrosion resistance. The 0.05–0.20% copper addition is what separates it from 1050 and 1060, and the absence of any heat treatment means the temper you specify is the strength you get — there is no later process to recover it. That trade is excellent for formed, welded, heat-transfer and conductive parts, and wrong for anything that has to carry load.
We supply 1100 in coil, plate, bar, tube, wire and profile, from O through H18, with cut-to-length and anodising handled in-house. Every order ships with an MTC, and low-MOQ custom production covers non-standard sizes and tempers within 10–60 days.
Send us your drawing or alloy specification, and we will confirm the temper, thickness and lead time before you commit to a PO.
Perguntas frequentes
Can 1100 aluminum be heat treated to increase strength?
No. 1100 is non-heat-treatable and hardens only by cold work, so strength comes from the H temper you order. There is no solution treatment, no aging step and no 1100-T6. If a drawing calls for one, the requirement needs rewriting as a temper plus a minimum strength.
What is the difference between 1100-O and 1100-H14?
O is annealed: typically about 90 MPa tensile, 35 MPa yield and roughly 35% elongation in sheet, which suits severe forming. H14 is half-hard: typically about 125 MPa tensile, 115 MPa yield and about 9% elongation. Choose O for post-delivery forming, and H14 when the part must hold shape in service.
Is 1100 suitable for electrical conductors?
Partly. At 59% IACS in the annealed condition it suits busbar, connectors, shielding and general conductor hardware. Overhead transmission and magnet wire are specified around 1350, which guarantees 61.5% IACS minimum. Substituting 1100 lowers the current rating, so the two are not interchangeable.
Can 1100 be used in marine or food-contact applications?
For food contact, yes: the alloy is non-toxic and resists many chemicals, which is why it appears in processing equipment and cookware. Strong alkalis are the exception. For marine service it resists salt atmosphere, but its low strength rules it out of load-bearing marine structure, where 5052 is the usual choice.
What 1100 forms, tempers and minimum order can you supply?
We supply coil, plate, bar, tube, wire and profile in O, H12, H14, H16 and H18, cut to length and anodised on request. Standard stock ships from inventory; non-standard sizes and tempers run at low MOQ with a 10–60 day lead time.
