1100 aluminum
Composition, temper, product-form and thickness boundaries for selecting, forming, joining, and specifying commercially pure 1100 aluminum.
Tags: materials, aluminum, wrought-aluminum, non-heat-treatable
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Identity and composition
Almetals' 1100-H14 coil-stock reference lists 16–21 ksi ultimate tensile strength and 14 ksi minimum yield. Its elongation over 2 inches rises from 1% at 0.009–0.012 inch to 5% at 0.051–0.113 inch and 6% at 0.114–0.250 inch. Almetals labels the table reference guidance and gives no controlling edition. Almetals H14 coil-stock limits
1100 is a registered wrought aluminum designation, not a temper, product specification, or guarantee of finished-part strength. The Aluminum Association's Teal Sheets, revised August 2018, identify 1100 as at least 99.00% aluminum, with 0.05–0.20% copper. Limits include combined silicon plus iron at 0.95%, manganese at 0.05%, zinc at 0.10%, and other elements at 0.05% each/0.15% total. Percentages are by mass. “Commercially pure” therefore does not mean chemically pure aluminum. Aluminum Association Teal Sheets, composition table
The same registration record lists 1100A separately, including different silicon-plus-iron, magnesium, and titanium limits. Do not silently drop that suffix or substitute another 1xxx grade because its minimum aluminum percentage looks similar. The designation system identifies composition; matching chemistry alone does not demonstrate compliance with every dimensional, mechanical, or surface requirement in an order. Aluminum Association designation system and 1100/1100A entries
Temper and strengthening
The temper suffix describes material condition. The Metals Service Center Institute distinguishes O as annealed to relieve strain hardening and improve ductility, H as strain hardened, and F as fabricated. Thus, 1100-O and 1100-H14 share an alloy designation but must remain separate entries in a material record. The letter in O is not a zero. MSCI aluminum temper guidance
1100 gains strength through cold work rather than precipitation heat treatment. H14 denotes a half-hard condition; it is not a promise that hardness, yield strength, and elongation are each halfway between two universal endpoints. Heating can remove strain hardening, so a supplied H temper cannot automatically be assigned to a locally heated region. ESAB's September 19, 2024 explanation distinguishes work hardening from precipitation hardening and explains how welding can anneal the heat-affected zone of non-heat-treatable alloys. ESAB strengthening and HAZ guidance
Typical properties are not acceptance minima
Kaiser's Tube & Pipe Alloy 1100, marked Rev. 05/06, gives the following typical mechanical properties. Its tensile table identifies a 0.0625-inch-diameter specimen and elongation over 4D. These data illustrate the temper tradeoff; they are not certified sheet properties or guaranteed procurement limits. Kaiser 1100 tube and pipe technical data, p. 1
| Temper | Typical ultimate tensile strength | Typical yield strength | Typical elongation/4D |
|---|---|---|---|
| O | 90 MPa | 35 MPa | 35% |
| H14 | 125 MPa | 115 MPa | 9% |
| H18 | 165 MPa | 150 MPa | 5% |
The same document reports nominal density 2.71 g/cm³ at 20°C, modulus 69 GPa, and thermal conductivity at 20°C of 222 W/(m·K) for O versus 218 W/(m·K) for H18. Retain the condition and reference temperature when using such values; the melting range is not a service-temperature rating. Kaiser typical physical properties, pp. 1–2
Product form and purchase specification
ASTM B209/B209M covers flat sheet, coiled sheet, and plate; its public 2021 scope identifies alloy/temper designations and gives A91100 as the UNS example for 1100. It also requires SI and inch-pound systems to be used independently for conformance. A conversion used for engineering comparison should not replace the ordered standard's original limit and rounding basis. Tube, wire, foil, or extruded products need their applicable product requirements rather than an assumed transfer of sheet properties. ASTM B209/B209M-21 public scope
A useful order states alloy, temper, product form, governing specification and edition, dimensions/tolerances, finish, and required certification. On receipt, reconcile those fields with the material certificate and lot identity. For example, a certificate for H14 coil does not satisfy an O-temper sheet order merely because both say 1100. Resolve substitutions before cutting, forming, or releasing parts.
Forming and machining
Austral Wright describes 1100 as readily cold formable in the annealed condition, with more limited ductility in H14/H24. Its stated annealed ductility example of up to 30% applies to 1.3–6.0 mm material. The supplier rates machinability poorly relative to its favorable formability. These are selection guides, not universal bend radii or cutting parameters. Its web sheet is undated and references AS/NZS 1734:1997, so its cited edition must not be mistaken for a current purchase requirement. Austral Wright 1100 description and fabrication guidance
For a formed part, qualify the actual temper and thickness with the intended tooling, bend direction, radii, and drawing acceptance criteria. Record cracking, springback, thinning, and surface damage as applicable. A successful bend in annealed stock does not validate the same operation in H18. Repeated forming also changes local condition; retain processing history when it matters to strength or subsequent operations.
Joining, corrosion, and finish boundaries
Harris offers 1100 MIG wire and TIG rod for joining 1xxx alloys, identifying ER1100/R1100 classifications in its published guide. A filler classification is a consumable designation, not certification of a base-metal sheet or a universal filler recommendation. Select for the actual base-metal combination, service, appearance, and qualified welding procedure. Harris aluminum product guide, pp. 6–7
Allow for HAZ softening when designing welded work-hardened 1100; parent-stock H14/H18 strength should not simply be assigned across the joint. ESAB non-heat-treatable alloy HAZ behavior
Corrosion resistance relies on the protective oxide film. Austral Wright notes both chemical-environment limits and galvanic effects when aluminum contacts other metals; anodizing can increase the protective film. Evaluate the actual fluid, temperature, exposure, crevices, and mating materials rather than treating “corrosion resistant” as chemical compatibility or food-contact approval. Austral Wright 1100 corrosion guidance
For welding preparation, AWS's August 2025 guidance emphasizes dry storage and removal of oxide/contamination shortly before welding. Choose cleaning and surface-finishing procedures that suit the joint and final appearance, then verify representative parts; a favorable alloy rating does not establish residue-free bonding or uniform decorative color. AWS aluminum storage and preparation