Pure Aluminium 1070A
Metallic shield for medium- and high-voltage cables
Pure Aluminium 1070A
Pure 1070A aluminium tape is a high-purity annealed material that provides electromagnetic shielding, short-circuit protection and mechanical reinforcement in medium- and high-voltage cables. Its electrical resistivity of 0.0281 µΩ/mm ensures uniform conductivity along the entire shield, enabling correct evacuation of fault currents and the safe operation of system protections.
In power-cable construction, pure aluminium is applied as a metallic shield over the insulation or over the phase bundle, providing a low-impedance path for short-circuit currents. Unlike polyester-laminated aluminium, the pure aluminium tape withstands the thermal and mechanical stresses of a short-circuit without backing degradation, making it essential in medium- and high-voltage cable constructions where shield integrity is critical.
Thicknesses range from 200 to 500 µm with tensile strength ≥60 MPa and elongation ≥15 % per ASTM D882/EN 13999. This range allows the optimum thickness to be selected based on the expected short-circuit current, the protection clearing time and the mechanical requirements of the installation.
In submarine cables, pure aluminium also provides impact and compression resistance, protecting the inner cable layers from mechanical stresses during laying and seabed operation. Thickness is selected based on installation depth and seabed conditions.
The annealing process gives the material the ductility needed to withstand forming during cable manufacturing without cracks or fissures, maintaining shield electrical continuity even at small bend radii.
How to choose the right one?
The right thickness depends primarily on the short-circuit current the shield must withstand and on the protection clearing time. Greater thickness means greater energy-absorption capacity during a short-circuit, but also greater finished-cable stiffness.
| Reference | Thickness | Tolerance | Typical application | When to choose |
|---|---|---|---|---|
| AL200 (1070A) | 200 µm | ±12 µm | MV cables up to 36 kV | Moderate fault currents, maximum flexibility |
| AL300 (1070A) | 300 µm | ±18 µm | MV/HV cables up to 72 kV | Protection/flexibility balance |
| AL400 (1070A) | 400 µm | ±24 µm | HV cables up to 145 kV | High short-circuit capacity |
| AL500 (1070A) | 500 µm | ±25 µm | HV cables, submarine | Maximum protection, severe stresses |
Technical specifications
The values shown below come from tests run to international standards and characterise the material's behaviour both during processing and in service.
| Property | Value | Test method |
|---|---|---|
| Alloy | 1070A | — |
| Temper | Annealed | — |
| Tensile strength | ≥60 MPa | ASTM D882 / EN 13999 |
| Elongation at break | ≥15% | ASTM D882 / EN 13999 |
| Electrical resistivity | 0.0281 µΩ/mm | Internal |
Available references
| Property | Nominal thickness (µm) | Tolerance (µm) |
|---|---|---|
| AL200 (1070A) | 200 | ±12 |
| AL300 (1070A) | 300 | ±18 |
| AL400 (1070A) | 400 | ±24 |
| AL500 (1070A) | 500 | ±25 |
Values shown are typical and do not constitute binding specifications.
Available variants
Alternative alloys
- 1050
- 1145
- 1200
- Temper H0
Annealing states
- Different annealing grades available per forming and application requirements
Consult availability and specifications for alternative alloys and tempers.
Delivery formats
Pure aluminium is supplied in jumbo reels optimised for continuous feed in high-voltage cable manufacturing lines. The formats are designed to minimise splices and maximise productivity.
Jumbo reel
Reel for continuous feed in manufacturing lines
Other formats and dimensions available on request. Custom slitting service available.
Application sectors
Need technical advice?
Our technical team is available to help you select the optimum material for your application.
We process material from our stock or material supplied by the customer.
Need technical advice?
Our technical team is available to help you select the optimal material for your application.
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