1350 Aluminium Wire Rod for Electrical Use
1350 wire rod is continuously cast and rolled EC aluminium, usually 9.5 mm in diameter, that cable makers draw into wire for overhead conductors, power cables and windings. ASTM B233 sets its tensile range by temper and a minimum conductivity of 61.3–61.5 % IACS for the drawn tempers. This guide summarises the requirements, the temper choice for your drawing line and what to check on delivery.
- Grade
- 1350 (Al ≥ 99.50 %)
- Common size
- 9.5 mm (3/8 in)
- Tempers
- O, H12, H13, H14, H16
- Main standard
- ASTM B233
What is 1350 wire rod?
Wire rod is the feedstock of the cable industry. Molten EC aluminium is cast continuously into a bar and rolled in one pass through a multi-stand mill into round rod, which is coiled at the end of the line. The rod is then drawn through a series of dies into wire of the size the conductor needs.
1350 is the grade for electrical conductors because it controls the impurities that cut conductivity, especially titanium, vanadium, chromium and manganese. Boron additions tie these elements up as insoluble borides. The result is rod with a conductivity close to 62 % IACS that draws easily without breaks.
Rod temper is controlled by the rolling and cooling conditions. Softer rod draws to finer sizes with fewer breaks and higher final conductivity; harder rod is used when the finished wire must reach a high tensile strength, such as H19 wire for ACSR and AAC conductors.
1350 chemical composition (wt %)
| Element | 1350 | 1370 |
|---|---|---|
| Silicon (Si) | ≤ 0.10 | ≤ 0.10 |
| Iron (Fe) | ≤ 0.40 | ≤ 0.25 |
| Copper (Cu) | ≤ 0.05 | ≤ 0.02 |
| Manganese (Mn) | ≤ 0.01 | ≤ 0.01 |
| Magnesium (Mg) | — | ≤ 0.02 |
| Chromium (Cr) | ≤ 0.01 | ≤ 0.01 |
| Zinc (Zn) | ≤ 0.05 | ≤ 0.04 |
| Boron (B) | ≤ 0.05 | ≤ 0.02 |
| Gallium (Ga) | ≤ 0.03 | ≤ 0.03 |
| Vanadium + titanium (V + Ti) | ≤ 0.02 | ≤ 0.02 |
| Others, each / total | ≤ 0.03 / ≤ 0.10 | ≤ 0.02 / ≤ 0.10 |
| Aluminium (Al) | ≥ 99.50 | ≥ 99.70 |
1370 is shown for comparison; see the 1370 wire rod guide for that grade.
Tensile and conductivity requirements by temper
ASTM B233 covers 1350 drawing stock from 9.5 to 25.4 mm (0.375 to 1.000 in) in diameter. The tensile ranges and conductivity minimums below are those of B233 for the drawn tempers; the H2x tempers carry the same limits as the corresponding H1x tempers.
| Temper | Tensile strength | Min. conductivity (% IACS) | Max. resistivity (Ω·mm²/m) |
|---|---|---|---|
| O (annealed) | Lowest; softest rod | Highest of all tempers | — |
| H12 / H22 | 83 – 117 MPa (12.0 – 17.0 ksi) | 61.5 | 0.028035 |
| H14 / H24 | 103 – 138 MPa (15.0 – 20.0 ksi) | 61.4 | 0.028080 |
| H16 / H26 | 117 – 152 MPa (17.0 – 22.0 ksi) | 61.3 | 0.028126 |
Upper tensile limits for H14 and H16 apply to rod up to 12.7 mm; for larger sizes they are agreed at enquiry. Always check the current edition of B233 and your contract, which may impose tighter ranges.
Mills also offer intermediate classes such as H13 and H11 under their own or national specifications. Choose the class with your wire drawer: softer rod for fine wire and windings, harder rod for H19 conductor wire.
Wire rod standards by market
| Standard | Market | Notes |
|---|---|---|
| ASTM B233 | Americas, Middle East, global | 1350 drawing stock for electrical purposes |
| EN 1715-2 | Europe | Drawing stock for electrical applications, including EN AW-1350 and EN AW-1370 |
| IS 5484 | India | EC grade aluminium rod produced by continuous casting and rolling |
| GOST 13843 | Russia, CIS | Aluminium wire rod for electrical purposes |
| GB/T 3954 | China | Electrical aluminium rod |
A product described as "to ASTM B221" is an extruded bar, not wire rod. B221 is the general extrusion specification and is not used for drawing stock.
Sizes, coils and linear mass
Typical supply
- Diameter
- 9.5 mm standard; also 7.6, 12, 15, 19, 24 and 25 mm
- Diameter tolerance
- About ± 0.3 – 0.5 mm depending on size and standard
- Coil
- Coils of roughly 1.5 – 2.5 t on pallets, strapped in at least three places
- Marking
- Tag with grade, temper, diameter, lot number and net weight on each coil
- Surface
- Clean, free of laps, cracks, inclusions, oil and oxide build-up
| Diameter (mm) | Area (mm²) | Linear mass (kg/m) |
|---|---|---|
| 7.6 | 45.4 | 0.123 |
| 9.5 | 70.9 | 0.192 |
| 12 | 113.1 | 0.306 |
| 15 | 176.7 | 0.478 |
| 19 | 283.5 | 0.767 |
| 24 | 452.4 | 1.224 |
| 25 | 490.9 | 1.328 |
What 1350 rod is drawn into
- Overhead conductors: AAC, ACSR, ACAR and ACSS strands in H19 and related tempers
- Insulated power cables: LV and MV cable cores, aerial bundled cable (ABC) phases
- Building wire: where codes allow aluminium conductors, usually in 8xxx alloys for small sizes
- Windings: enamelled round and rectangular wire for transformers and motors
- Earthing and bonding: conductors, tapes and braid
What to check when rod arrives
- CertificateChemistry including V + Ti and B, conductivity or resistivity, tensile and elongation for each lot.
- ConductivitySpot-check by resistivity bridge or eddy current; temper drift shows as a change in tensile and conductivity.
- Surface and coilInspect for laps, slivers and mechanical damage; check coil form and strapping so pay-off is smooth.
- Twist testA torsion test on rod samples reveals laps and internal defects that cause breaks on the drawing line.
References and standards
- ASTM B233 – Standard Specification for Aluminum 1350 Drawing Stock for Electrical Purposes
- EN 1715-2 – Aluminium and aluminium alloys. Drawing stock. Specific requirements for electrical applications
- IS 5484 – EC grade aluminium rod produced by continuous casting and rolling
- GOST 13843 – Aluminium wire rod. Specifications
- The Aluminum Association – Aluminum Electrical Conductor Handbook
1350 aluminium wire rod: frequently asked questions
What is the standard diameter of 1350 wire rod?
9.5 mm (3/8 in) is the industry standard. Larger sizes such as 12, 15, 19 and 25 mm are used for heavy conductors and special drawing lines.
What conductivity does ASTM B233 require?
Minimums of 61.5 % IACS for H12, 61.4 % for H14 and 61.3 % for H16 at 20 °C, with the corresponding maximum resistivities.
Which temper is best for drawing fine wire?
Softer rod, such as O or H12, gives fewer breaks and higher conductivity in fine and winding wire. Harder rod suits high-strength conductor wire.
Is 1350 wire rod the same as EC grade rod?
Yes. EC (electrical conductor) grade is the trade name for 1350-type aluminium; Indian IS 5484 and European EN 1715-2 use their own designations for the same class of material.
Do you supply rod with test certificates?
Yes. Each lot ships with a mill test certificate giving chemistry, conductivity and tensile results, packed for export.
Buying 1350 wire rod?
Send diameter, temper, standard and volume. We will reply with specification, certification and delivered pricing.
