What Is 1350 Aluminum?
1350 is a 1xxx-series alloy with a minimum aluminum content of 99.50%, and it is the alloy the Aluminum Association designates as EC (Electrical Conductor) grade. It is not heat-treatable — it gains what little strength it has through cold-work strain hardening, not through solution treatment and aging like 6xxx or 2xxx alloys.
That purity is the whole point: iron and silicon are held to low limits specifically to protect electrical conductivity, which makes 1350 the standard choice for wire, busbar, and transformer windings rather than for structural parts. The defining trade-off is maximum conductivity at the cost of low strength — and that trade-off is exactly why the temper you pick (O for forming, H19 for strength) matters more than any other specification.
1350 Aluminum Chemical Composition
1350 is controlled almost entirely by impurity ceilings, because the base metal is already 99.5% aluminum. Iron and silicon are the two elements most damaging to conductivity, so their limits are tight.
| Element | Content (max unless noted) |
|---|---|
| Aluminum (Al) | 99.50% minimum (balance) |
| Silicon (Si) | 0.10% |
| Iron (Fe) | 0.40% |
| Copper (Cu) | 0.05% |
| Manganese (Mn) | 0.01% |
| Magnesium (Mg) | 0.01% |
| Chromium (Cr) | 0.01% |
| Zinc (Zn) | 0.05% |
| Titanium (Ti) | 0.02% |
| Others (each / total) | 0.03% / 0.10% |
The iron-to-silicon ratio also matters in practice: EC-grade conductor wire is typically specified with Fe + Si controlled so the sum stays low enough to protect conductivity. For electrical use, the composition table above is the acceptance basis (ASTM B230 / B233, EN AW-1350, GB 1A35).
1350 Aluminum Physical and Mechanical Properties
The single number that defines 1350 is its electrical conductivity — a guaranteed minimum of 61.2% IACS (International Annealed Copper Standard), commonly specified at 61.8% IACS. That is the highest conductivity of any mainstream wrought aluminum alloy and the reason copper is replaced by 1350 in weight-sensitive conductors.
| Property | Value |
|---|---|
| Density | 2.70 g/cm³ |
| Melting range | 646–657 °C |
| Electrical conductivity | ≥ 61.2% IACS (commonly 61.8% IACS) |
| Thermal conductivity | ~234 W/(m·K) |
| Modulus of elasticity | ~68.9 GPa |
| Tensile strength, O temper | 60–100 MPa |
| Tensile strength, H19 temper | 150–200 MPa |
| Yield strength, O temper | 20–50 MPa |
| Yield strength, H19 temper | 145–185 MPa |
| Elongation, O / H19 | ≥ 20% / ≥ 1.5% |
Conductivity stays essentially constant across tempers — about 61.8% IACS in both O and H19 — so selecting H19 for strength does not cost you current-carrying capacity. The mechanical numbers above are for wire per ASTM B230; sheet and other forms scale with the same cold-work logic but use form-specific values.
Common Tempers of 1350 Aluminum
1350 is strengthened only by cold working (strain hardening), never by heat treatment. Starting from the fully soft O condition, each H1x step applies more reduction and partial annealing to raise strength at the expense of elongation.
| Temper | Strain-hardening level | Typical UTS (MPa) | Best for |
|---|---|---|---|
| O | Fully annealed, soft | 60–100 | Drawing, winding, tight bends |
| H12–H18 | Progressive cold work between O and H19 | Rises from ~90 toward ~170 across the ladder | Formed conductors needing more rigidity than O |
| H19 | Full hard (standard EC wire) | 150–200 | Overhead conductors, busbar, cable cores |
H19 is the commercial workhorse: it is the temper specified for hard-drawn EC wire in ASTM B230 and for concentric-lay stranded conductors (AAC/ACSR) in ASTM B231. If the application is a drawn wire, stranded cable, or busbar, H19 is almost always the call. O is reserved for magnet wire, fine drawing, and flexible conductors where formability dominates.
Go/No-Go Limits
Use this list to decide whether 1350 fits before you spec it.
Go — use 1350 when:
- Maximum electrical conductivity at minimum weight is the priority — overhead lines, busbar, and transformer or motor windings where 61.2% IACS matters more than strength.
- The part is non-structural and formed or drawn into shape — magnet wire, coil winding, and flexible conductors take advantage of O-temper formability.
- Corrosion resistance in ordinary atmospheric or mildly chemical service is enough — the pure aluminum oxide film protects exposed outdoor conductors without coating.
- A copper replacement is wanted for weight or cost, and the design can accept aluminum’s lower conductivity-to-copper ratio (~61% vs 100% IACS).
No-Go — do not use 1350 when:
- The component carries mechanical load — 1350-H19 reaches only about 150–200 MPa tensile, far below structural grades like 6061-T6 (310 MPa) or 6082-T6.
- Hardness or wear resistance is a requirement — the alloy is soft even at H19 and will gall or scratch under sliding contact.
- Service temperature is high and strength must hold — like all aluminum, 1350 loses notable strength above roughly 150 °C, so it is not a high-temperature structural material.
- The part needs threading, repeated flexing under load, or machined load paths — its low yield and hardness make it a poor structural choice.
Where 1350 Aluminum Is Used
The Go/No-Go criteria above separate “should I?” from “where?”. The list below maps the systems where 1350 is standard practice.
Power Transmission and Distribution
Overhead conductors are the largest use: all-aluminum (AAC) and aluminum conductor steel-reinforced (ACSR) lines are built from hard-drawn 1350-H19 wires because they carry the most current per kilogram of any common overhead conductor family. Underground cable cores, substation bus work, and transformer windings use the same EC-grade conductivity, with O-temper wire where flexibility during installation matters.
Magnet Wire, Coil Winding, and Busbar
Motors, generators, and transformers use 1350-O for magnet wire and fine coil winding, where extreme formability and highest conductivity win. Busbar — both solid and stranded — uses H19 for rigid, high-current distribution in switchgear and power electronics. For EC-grade wire forms, see Linsy’s 1350-O/H19 aluminum wire.
1350 vs 6061 vs 8000 — How to Choose
These three are not competitors; they answer different questions. 1350 is the conductivity grade, 6061 is the structural grade, and 8000-series fills niche conductor roles.
| Property | 1350 (EC grade) | 6061-T6 | 8000-series conductor grades |
|---|---|---|---|
| Primary role | Electrical conductivity | Structural strength | Specialty conductors (some building wire) |
| Electrical conductivity | 61.2% IACS (min) | ~40% IACS | Typically below 61.2% IACS |
| Tensile strength | 60–200 MPa (by temper) | 310 MPa | ~100–200 MPa |
| Heat treatment | No (cold-work only) | Yes (T6) | Varies by grade |
| Corrosion resistance | High (purity) | High (less than 1350) | Good, alloy-dependent |
| Typical use | Wire, busbar, windings | Frames, machined parts | Specific 8000 conductor specs |
Pick 1350 when conductivity per weight is the constraint. Pick 6061-T6 when the part must carry load and welding or machining is involved. Consider an 8000-series grade (for example 8176 or 8130 building wire) only when a specific standard or alloying benefit — not higher conductivity — drives the spec; 1350 still leads on pure IACS performance. For the structural alternative, see the 6061 aluminum alloy page.
Working with 1350 Aluminum
Forming and drawing: In the O temper, 1350 is extremely formable — it draws, bends, and winds without difficulty, which is why it is the default for magnet wire and fine conductors. H19 loses most of that ductility (elongation drops to about 1.5%), so form it before final hardening or use it as-drawn.
Welding and joining: 1350 welds well by resistance methods (used for conductor splicing) and can be joined by MIG/TIG with appropriate filler, though welding is uncommon in standard conductor manufacturing. Note that welding does not heat-treat the alloy — there is no T-temper to restore.
Corrosion protection: The high purity gives 1350 excellent atmospheric corrosion resistance through its natural oxide film, so most outdoor conductor uses need no coating. In chloride or industrial environments, the same anodizing, painting, or sleeving used on other aluminum grades applies.
No heat treatment: Because 1350 is not heat-treatable, strength comes only from cold work. Any annealing step returns it toward O temper; restoring H19 requires redrawing, not oven treatment. Plan the fabrication route around the final temper.
Pros and Limitations at a Glance
| Dimension | Strength | Limitation |
|---|---|---|
| Electrical conductivity | Highest of any common aluminum alloy (≥61.2% IACS) | Still ~61% of copper — not a copper replacement where space is fixed |
| Weight | ~1/3 the weight of copper for equal current | Low strength limits structural use |
| Formability (O) | Excellent for drawing and winding | H19 is brittle in tight bends |
| Corrosion resistance | High from purity, no coating needed outdoors | Soft surface galls under sliding wear |
| Cost | Cheaper and lighter than copper conductors | Low mechanical properties restrict applications |
| Availability | Standard EC grade, broad mill supply | Not a stock structural section grade |
Conclusion
1350 aluminum delivers the highest conductivity of any mainstream wrought aluminum alloy — a guaranteed 61.2% IACS minimum — but its trade-off is low strength and hardness that rules it out for load-bearing parts. That makes it the right call for conductors, busbar, and windings, and the wrong call for anything structural.
Linsy Aluminum, a Shenzhen-based factory with more than 20 years of experience, supplies 1350 in wire, busbar, sheet, and coil across the 1000–8000 series, including 1350-O and 1350-H19 ec wire, with full MTC documentation per order and SGS test reports available on request; typical custom lead time runs 10–60 days with low-MOQ support for non-stock sizes. When the specification calls for EC-grade 1350, send the drawing or conductor specification for a grade-and-temper review.
Frequently Asked Questions
What is the difference between 1350-O and 1350-H19?
1350-O is fully annealed and soft, with elongation of 20% or more — best for drawing, winding, and tight bends. 1350-H19 is full-hard strain-hardened to 150–200 MPa tensile, the standard temper for overhead conductors and busbar where strength matters more than formability. Conductivity is the same (~61.8% IACS) in both.
Is 1350 aluminum suitable for structural applications?
No. Even at H19, 1350 reaches only about 150–200 MPa tensile, far below structural grades such as 6061-T6 (310 MPa). It is a conductor grade, not a structural grade, and should be limited to non-load-bearing electrical uses.
What is the difference between 1350 and 1370 aluminum?
Both are EC-grade pure alloys, but 1370 has a higher minimum purity of 99.70% aluminum versus 1350’s 99.50%, giving slightly better conductivity. Both serve electrical conductors; 1370 is specified when the application calls for the higher-purity grade.
Can 1350 aluminum be heat treated to increase strength?
No. 1350 is not a heat-treatable alloy — it gains strength only through cold-work strain hardening (the H1x tempers). Annealing returns it toward O, and restoring H19 requires redrawing, not an oven cycle.
What is the difference between 1350 and 1050 aluminum?
Both are 99.5%-minimum pure alloys, but 1350 is tuned for electrical use with iron and silicon held low to protect conductivity, while 1050 is a general-purpose pure grade. Choose 1350 when electrical performance is the priority and 1050 for general forming and fabrication.
