Transformer aluminum strip is widely used as a conductive winding material for oil-immersed transformers, dry-type transformers, power transformers, distribution transformers and reactors. With good electrical conductivity, stable mechanical properties, smooth surface and precise slitting tolerance, aluminum strip is an economical and reliable choice for transformer winding.
Haomei Aluminum supplies high-quality aluminum strip for transformer winding, including 1050, 1060, 1070 and 1350 aluminum strip coils. Custom thickness, width, temper and coil weight are available according to transformer design requirements.
Transformer aluminum strip coil with smooth surface and accurate dimensions.
Electrical grade transformer aluminum strip with clean and flat surface.
Transformer aluminum strip with precise slitting edge and low burr.
High conductivity aluminum strip for transformer winding material.
What is Transformer Aluminum Strip?
Transformer aluminum strip is a high conductivity aluminum material used for winding coils in electrical transformers. It is widely used in dry type transformers, oil immersed transformers and distribution transformers.
Compared with traditional copper winding materials, aluminum strip provides excellent electrical conductivity, lighter weight and lower cost, making it an important conductor material in modern transformer manufacturing.
Transformer Aluminum Strip Specifications
| Item | Specification |
| Product Name | Transformer Aluminum Strip |
| Material | Aluminum / Aluminium |
| Alloy | 1050, 1060, 1070, 1100, 1350 |
| Temper | O, H12, H14, H16, H18 |
| Thickness | 0.2 mm - 3.0 mm, customizable |
| Width | 10 mm - 1600 mm, customizable |
| Inner Diameter | 300 mm, 405 mm, 505 mm or customized |
| Surface | Bright, clean, smooth, oil-free or lightly oiled |
| Edge | Slit edge, rounded edge available |
| Conductivity | High electrical conductivity, depending on alloy |
| Application | Transformer winding, reactor winding, electrical equipment |
| Packaging | Wooden pallet, wooden case, moisture-proof packaging |
Need high-quality transformer aluminum strip with stable performance and factory price?
Our aluminum strip for transformer winding delivers a perfect balance of performance, durability, and affordability. Contact Haomei Aluminum today for technical support and fast quotation.
Common Alloys for Transformer Aluminum Strip
Haomei supplies electrical grade aluminum strip in various alloys for transformer winding, including 1050, 1060, 1070 and 1350 aluminum strip with custom dimensions and soft temper.
1050 Transformer Aluminum Strip
1050 aluminum strip has high aluminum purity and good electrical conductivity. It is widely used in transformer winding, electrical equipment, cable wrapping and conductive components.
1060 Transformer Aluminum Strip
1060 aluminum strip is one of the most commonly used materials for transformer winding. It offers good conductivity, excellent formability and stable quality for industrial use.
1070 Transformer Aluminum Strip
1070 aluminum strip has higher aluminum content and better electrical performance. It is suitable for transformer products requiring higher conductivity and stable winding.
1350 Transformer Aluminum Strip
1350 aluminum strip is an electrical grade aluminum material with excellent conductivity. It is widely used in transformer winding, conductors and power equipment.
Temper: Almost all are supplied in O temper (soft annealed). After full annealing, the strip offers excellent winding performance and elongation, preventing cracking during coil winding.
| Grade | Aluminum Content | Conductivity | Features |
| 1050 (O) | 99.50% | Good | Moderate cost, well-balanced performance |
| 1060 (O) | 99.60% | Excellent | Slightly higher conductivity than 1050 |
| 1070 (O) | 99.70% | Very High | High purity, low resistivity |
| 1350 (O) | 99.50%+ | Ultra High | Electrical-grade pure aluminum, conductivity close to 62% of copper |
Transformer Aluminum Strip – Surface and Edge Quality Requirements
In transformer winding applications, surface condition and edge precision directly influence insulation safety and winding stability. Even small defects can cause damage to insulation paper or affect long-term transformer performance. That is why Haomei applies strict quality control across every production stage.
Stable Surface Quality
Each coil is processed to ensure a clean and uniform surface suitable for precision winding and insulation compatibility.
- No visible contamination or oil residue
- No severe scratches or pressing marks
- Controlled oxidation level for electrical use
Dimensional Consistency
Accurate geometry ensures smooth processing on automated winding lines and stable stacking performance.
- Uniform thickness across full coil length
- Tight width tolerance control
- Good coil flatness for stable unwinding
Precision Slitting Edge
Edge quality is optimized to reduce mechanical damage during high-speed winding and insulation wrapping.
- Low burr slitting technology
- Smooth edges to protect insulation paper
- Reduced cracking risk during forming
Customized Coil Supply
To support different transformer designs and production systems, we offer flexible coil configurations.
- Custom inner diameter options
- Adjustable coil weight for handling systems
- Stable mechanical properties for continuous processing
Strict quality inspection is applied to every batch to ensure stable winding performance, reduced defect risk, and reliable transformer operation in real production environments.
Transformer Aluminum Strip Features
As a key conductive material for transformer windings, the quality of aluminum strip directly affects the performance and reliability of the entire transformer. We select high-purity aluminum and apply precision processing to ensure every coil consistently meets the stringent requirements of power equipment.
Stable and Reliable Electrical Conductivity
Conductivity reaches 60%–62% of copper, achieving an excellent balance between performance and cost. High-purity raw material ensures consistent resistivity, reduces energy loss, and improves overall transformer efficiency.
Strict Surface and Dimensional Control
From rolling to slitting, the entire process is tightly controlled. The strip is clean and flat, free of oil, scratches, and oxidation spots, with precise thickness and width tolerances to ensure consistent winding resistance and structure, making winding smoother and finished products more stable.
Burr-Free Rounded Edges for Higher Safety
Using special precision cutting and edge rounding processes, the edges are smooth and burr-free, preventing insulation damage during winding and greatly reducing the risk of short circuits, improving long-term safety and reliability.
Flexible and Durable for Complex Winding Structures
Fully annealed (O temper) aluminum strip offers excellent elongation (≥25%), is not easy to crack or break during winding, and easily adapts to multi-layer, multi-angle, and special-shaped coil structures, improving production efficiency and yield.
Good Heat Dissipation, Corrosion Resistance, Longer Service Life
Excellent thermal conductivity helps reduce operating temperature, while aluminum’s natural corrosion resistance ensures stable performance even in long-term service environments.
Lightweight with Clear Cost Advantages
Under the same conductivity requirement, aluminum’s density is only about 30% of copper, helping reduce transformer weight by more than 40%. At the same time, material cost is only about 1/3–1/4 of copper, providing a highly competitive overall cost advantage for transformer manufacturers.
Transformer Aluminum Strip Chemical Composition
Chemical Composition of 1050 Transformer Aluminum Strip
| Element | Al | Si | Fe | Mg | Zn | Mn | Ti | Cu | V |
| Standard Value | ≥99.5 | 0.0431 | 0.203 | 0.0013 | 0.0093 | 0.0104 | 0.02 | 0.0022 | 0.0039 |
Chemical Composition of 1060 Transformer Aluminum Strip
| Element | Al | Si | Fe | Mg | Zn | Mn | Ti | Cu | V |
| Standard Value | ≥99.6 | 0.0431 | 0.203 | 0.0013 | 0.0093 | 0.0104 | 0.02 | 0.0022 | 0.0039 |
Chemical Composition of 1070 Transformer Aluminum Strip
| Element | Al | Si | Fe | Mg | Zn | Mn | Ti | Cu | V |
| Standard Value | ≥99.7 | 0.0431 | 0.203 | 0.0013 | 0.0093 | 0.0104 | 0.02 | 0.0022 | 0.0039 |
Chemical Composition of 1350 Transformer Aluminum Strip
| Element | Al | Si | Fe | Mg | Zn | Mn | Ti | Cu | V |
| Standard Value | ≥99.5 | 0.0431 | 0.203 | 0.0013 | 0.0093 | 0.0104 | 0.02 | 0.0022 | 0.0039 |
Mechanical Properties of Transformer Aluminum Strip
| Alloy | Thickness /mm | Temper | Tensile strength MPa | Elongation (%) |
| 1050, 1060, 1070, 1350 | 0.08-0.20 | O | 60-95 | ≥20 |
| >0.20-3.00 | ≥25 |
Transformer Aluminum Strip Thickness Tolerance
| Thickness | Thickness Tolerance |
| 0.1-0.2 | +/-8% |
| 0.2-0.4 | +/-0.02 |
| 0.4-0.8 | +/-0.03 |
| 0.8-1.1 | +/-0.04 |
| 1.1-1.4 | +/-0.05 |
| 1.4-2.0 | +/-0.06 |
| 2.0-2.5 | +/-0.07 |
| 2.5-3.0 | +/-0.08 |
Transformer Aluminum Strip Width tolerance
| Thickness(mm) | Width tolerance(%) | ||||
| <100 | 100-300 | 300-500 | 500-1250 | 1250-1500 | |
| >0.1-0.20 | +/-0.15 | +/-0.2 | +/-0.3 | +/-0.5 | +/-0.5 +/-1 |
| 0.20-0.60 | +/-0.15 | +/-0.2 | +/-0.3 | +/-0.75 | +/-0.5 +/-1.25 |
| 0.60-1.0 | +/-0.15 | +/-0.25 | +/-0.5 | +/-0.75 | +/-0.5 +/-1.25 |
| 1.0-2.0 | +/-0.2 | +/-0.35 | +/-0.6 | +/-1 | +/-0.5 +/-1.25 |
| 2.0-3.0 | +/-0.5 | +/-0.5 | +/-0.75 | +/-1 | +/-0.5 +/-1.25 |
Transformer Aluminum Strip Burrs and collapse
| The width of aluminium strip (mm) | Burr’s height (mm) | Collapsed side’s height (mm) |
| <0.2 | 0.01 | ≥0.05-0.1 |
| 0.2-1.0 | 0.015 | |
| 1.1-1.5 | 0.02 | |
| >1.6 | 0.03 |
Transformer Aluminum Strip Winding Structure & Design
Aluminum Strip Coil
- Rolled from high-purity aluminum with a flat strip cross-section
- Continuously wound into coils during the manufacturing process
- Compared with round wire, aluminum strip offers a higher filling factor, better heat dissipation, and more uniform mechanical strength
Primary Winding
- The input winding located on one side of the iron core, usually connected to the power grid
- Formed by multi-layer winding of aluminum strips
- Relatively fewer turns with larger current
- Responsible for converting input electrical energy into magnetic energy
Secondary Winding
- The output winding located on the other side of the iron core, supplying power to the load
- Also wound using aluminum strips
- The number of turns is designed according to the transformation ratio and is usually greater than that of the primary winding
- Outputs high voltage or low voltage (depending on the design)
Insulation Layer
- A critical structure positioned between each layer of aluminum strip
- Common materials: electrical insulation paper, insulating films, and composite insulation materials
- Prevents interlayer short circuits
- Also helps form oil ducts or air ducts to improve heat dissipation
Laminated Iron Core
- The magnetic circuit core of the transformer
- Laminated from silicon steel sheets to reduce eddy current losses
- Provides a closed magnetic flux path for the primary and secondary windings
- Determines the transformer’s efficiency and no-load losses
Cooling Channels
- Heat dissipation channels reserved between the windings and the iron core, as well as within the windings
- Facilitate the circulation of transformer oil or air
- Reduce operating temperature rise of the windings
- Especially important for aluminum strip windings (high-current, low-loss designs)
Clamping Frame
- Used to mechanically secure the iron core and windings
- Prevents winding deformation during transportation or short-circuit impacts
- Enhances overall mechanical strength
- Reduces operating noise
High Voltage Bushings
- High-voltage terminals of the transformer
- Provide electrical insulation and mechanical support
- Safely conduct electrical energy from the windings to external circuits
- Commonly used in oil-immersed and dry-type transformers
Low Voltage Output / High Voltage Output
- Low Voltage Output: low-voltage side output with high current
- High Voltage Output: high-voltage side output with high voltage
Transformer Aluminum Strip Applications
Dry-type Transformer Winding
Transformer aluminum strip is widely used in low-voltage windings of dry-type transformers. As a high-performance aluminum strip for transformers, it features stable electrical conductivity, excellent formability, and corrosion resistance, ensuring long-term safe operation of the windings. It is a proven and mature choice for power equipment manufacturers.
Oil-immersed Distribution Transformer
In medium- and low-voltage windings, aluminum winding strip has become one of the mainstream conductor materials. Compared with copper, electrical aluminum strip significantly reduces cost while maintaining electrical performance, making it an ideal solution for high cost-performance distribution transformer design.
Substation & Reactor
High-quality transformer aluminum strip is suitable for windings in substations and reactors, providing uniform conductivity and good thermal stability, improving overall reliability and service life of power equipment.
Renewable Energy
In photovoltaic inverters and wind power transformers, aluminum strip for transformers is widely applied. Its lightweight and high-efficiency conductivity advantages help improve energy conversion efficiency and reduce overall system cost.
High-frequency Transformer
Some high-frequency electronic transformers use aluminum winding strip to replace copper strip. While meeting high-frequency electrical performance requirements, it achieves lightweight design and cost optimization, especially suitable for electronic power supplies and renewable energy power systems.
Distribution Transformer
Whether pole-mounted transformers or box-type distribution transformers, electrical aluminum strip is one of the standard winding materials, providing stable and reliable power transmission for the grid.
Renewable Power Grid
In inverters and step-up transformers for solar and wind grid-connection systems, transformer aluminum strip helps improve overall system reliability and service life thanks to its good conductivity and durability.
Why Choose Aluminum Strip in Transformer Winding?
Transformer manufacturers choose aluminum strip for transformer winding because it provides reliable electrical performance, lower weight and better cost efficiency.
- Good electrical conductivity – Electrical-grade transformer aluminum strip can meet the conductivity requirements of many transformer winding applications.
- Lower weight – Aluminum has lower density than copper, helping reduce the total transformer weight and improve transportation efficiency.
- Cost-effective material – Transformer aluminum strip offers better cost control compared with copper strip for large-scale production.
- Good winding performance – Soft temper aluminum strip has good flexibility and is suitable for stable winding in transformer manufacturing.
- Corrosion resistance – Aluminum naturally forms an oxide layer, providing good corrosion resistance in long-term use.
- Custom size availability – Thickness, width, coil weight and inner diameter can be customized according to transformer production requirements.
Transformer Aluminum Strip Packaging
Proper packaging is essential to protect aluminum strip during long-distance transportation. Haomei Aluminum provides export-standard packaging solutions to ensure safe delivery.
- Moisture-proof paper wrapping to prevent humidity damage
- Plastic film wrapping for surface protection and cleanliness
- Strong wooden pallet base for stable handling and stacking
- Wooden case packaging for enhanced export protection
- Eye-to-wall or eye-to-sky coil packaging options available
- Customized coil weight and packing method according to customer requirements
- Each coil labeled with alloy, temper, thickness, width, coil number, and production batch for easy identification
Comparison Between Aluminum Strip Transformers and Copper Winding Transformers
Although copper is a better conductor, aluminum has significant advantages in logistics and economics.
- Cost: Aluminum is about 30–50% cheaper than copper, and its price is usually more stable in the global market.
- Weight: Aluminum density (2.7 g/cm³) is about one third of copper (8.96 g/cm³). Although aluminum windings require a larger cross-sectional area to carry the same current, the final transformer is still much lighter.
- Thermal performance: Aluminum strip dissipates heat more evenly than round copper wire, reducing “hot spots” that cause insulation aging.
- Space: The main drawback is that, at the same current, aluminum requires about 66% more cross-sectional area than copper, resulting in a larger overall transformer size.
| Feature | Aluminum Strip Transformer | Copper Strip/Wire Transformer |
| Cost | Low (significant material cost advantage) | High |
| Weight | Light (about 30%–40% lighter) | Heavy |
| Size | Larger (for the same capacity) | Compact |
| Conductivity | Lower (requires larger cross-sectional area) | Excellent |
| Connection Reliability | High requirements, complex process | Easy, mature process |
| Short-circuit Withstand Ability | Requires reinforced design | Inherent advantage |
| Long-term Temperature Rise | Can meet standards with proper design | Usually lower |
| Main Market | Cost-sensitive distribution transformers, dry-type transformers | Medium & large power transformers, high-reliability applications |
Why use aluminum strip instead of traditional copper wire/copper strip?
The core driving forces are cost and weight:
- Significant cost advantage: The price of aluminum is much lower than copper (about one third of copper), which can greatly reduce raw material cost in mass-produced transformers.
- Lightweight: The density of aluminum is about one third of copper, making the transformer much lighter and easier for transportation and installation.
- Resource and strategic considerations: Aluminum resources are relatively abundant, and using aluminum helps reduce dependence on copper resources.
Transformer Aluminum Strip Selection Guide
Key Points for Selecting and Using Transformer Aluminum Strip
- Material selection: Choose the appropriate grade according to transformer capacity and voltage class (1060 for medium and high voltage, 1050 for low voltage).
- Temper confirmation: Must be O temper; avoid using H temper (half-hard / hard), which will affect winding performance.
- Surface quality: Check that the surface is free from scratches and burrs, with uniform chamfered edges.
- Dimensional accuracy: Strictly control thickness tolerance, as it directly affects coil resistance and loss.
- Connection process: Use ultrasonic welding or special aluminum-copper transition connectors to avoid excessive contact resistance.
With its outstanding cost-performance ratio and lightweight advantages, transformer aluminum strip has become the mainstream choice in modern transformer manufacturing, especially for dry-type transformers. Through proper design (increasing cross-sectional area to compensate for lower conductivity) and process optimization, aluminum strip transformers can fully meet the performance requirements of power systems and are an ideal solution for saving energy and reducing costs.
Select Aluminum Alloy Grade Based on Transformer Type
Choosing the correct alloy ensures stable conductivity and mechanical performance during winding.
Common alloys for transformer aluminum strip:
1060 / 1070 Aluminum
Widely used in distribution transformers due to high electrical conductivity and excellent formability.
1350 Electrical Grade Aluminum
Specifically designed for electrical conductors. Offers consistent conductivity and low resistivity, ideal for large current windings.
Different types of transformers have varying performance requirements for aluminum strips. The appropriate alloy grade should be selected according to the specific application scenario:
Dry-Type Transformers
Typically, 1060 or 1070 grade aluminum strips are selected. These materials have high purity and good electrical conductivity, meeting the performance requirements of dry-type transformers.
Oil-Immersed Transformers
1050 or 1060 grade aluminum strips can be used. These materials have good corrosion resistance and workability, making them suitable for use in oil-immersed environments.
Special Transformers
For example, high-frequency transformers and pulse transformers may require specialized electrical aluminum strips such as 1350, which offer higher conductivity and more stable electrical performance.
Selection tip:
For transformer windings, electrical conductivity should always be prioritized over strength. Alloys with higher purity deliver lower losses and better energy efficiency.
Select Specifications Based on Technical Parameters
When selecting transformer aluminum strips, the specifications should be chosen based on specific technical parameter requirements:
- Thickness selection: The thickness of the aluminum strip should be determined based on the transformer's rated capacity, operating voltage, and winding structure. Generally, the larger the capacity and higher the voltage, the thicker the aluminum strip required.
- Width selection: The width of the aluminum strip should be based on winding design requirements and winding processes, while also considering the capacity of winding equipment.
- Conductivity requirements: Select aluminum strips with appropriate conductivity based on the transformer's efficiency requirements and loss limitations. Generally, the higher the conductivity, the lower the winding loss—but the higher the cost.
- Mechanical performance requirements: Choose aluminum strips with appropriate tensile strength and elongation based on the winding process and structure to ensure no breakage or excessive deformation occurs during winding.
Cost-Performance Analysis and Long-Term Cost Consideration
When selecting transformer aluminum strips, one should not only consider the initial purchase cost, but also conduct a comprehensive cost-performance analysis and long-term cost evaluation:
Cost Factor Analysis
- Initial cost: Compare quotations from different suppliers, including material cost, processing cost, and transportation cost.
- Operating cost: Consider the impact of aluminum strip conductivity on transformer losses and calculate the energy consumption cost during long-term operation.
- Maintenance cost: Consider how the quality of aluminum strips affects transformer maintenance frequency and cost.
- Service life: Evaluate how the quality and performance of aluminum strips affect transformer lifespan, and calculate the total lifecycle cost.
- Reliability value: Consider the potential value brought by the improved reliability and safety of the transformer due to high-quality aluminum strips.
By comprehensively considering these factors, one can choose the most cost-effective transformer aluminum strip product to achieve long-term economic and technical benefits.
Transformer Aluminum Strip Production Process
Raw Material Preparation
Select aluminum ingots with appropriate purity, perform accurate ingredient calculation, and carry out impurity removal and preheating treatment to ensure impurity content ≤0.02%. High-quality raw materials are the foundation for producing high-quality transformer aluminum strips.
Melting and Refining
Add pretreated aluminum ingots and alloying elements into the melting furnace and heat to 700–800℃ for melting. Stir uniformly for 30–45 minutes. Use gas blowing and filtration to remove impurities and gases, and precisely control the molten aluminum temperature to prepare for subsequent casting.
Casting and Ingot Treatment
Pour the molten aluminum into molds to form ingots, control the cooling rate to avoid internal stress and defects, and perform homogenization treatment to improve internal structure and ensure uniform grain structure.
Rolling and Heat Treatment
Heat the ingot to 550–580℃ for hot rolling. Further reduce thickness through cold rolling to the target thickness. Perform final annealing on the cold-rolled aluminum strip to obtain the desired O temper (soft condition), improving flatness and surface quality.
Finishing and Surface Treatment
Slit the aluminum strip to the required width, chamfer and deburr the edges, clean the surface to remove oil and impurities, and perform surface treatments such as passivation or coating as needed to enhance corrosion resistance and insulation performance.
Quality Control and Inspection
Conduct comprehensive quality inspections on incoming raw materials, key process parameters during production, and finished products. Tests include chemical composition analysis, conductivity testing, mechanical property testing, dimensional measurement, and visual inspection. Establish a complete quality traceability system.
Why Choose Haomei Aluminum?
Haomei Aluminum is an experienced aluminum strip supplier from China, specializing in aluminum strip coils for transformer winding and other electrical applications.
- Rich production experience in aluminum strip manufacturing for electrical applications
- Alloy options available: 1050, 1060, 1070, and 1350 aluminum strip
- Custom specifications including thickness, width, and coil dimensions
- Strict slitting and edge control for transformer-grade quality requirements
- Stable performance quality suitable for transformer winding applications
- Competitive factory pricing for global wholesale buyers
- Export-standard packaging ensuring safe international transportation
- Fast quotation and delivery support for urgent project needs
- Mill Test Certificate (MTC) provided for quality assurance
If you are looking for a reliable transformer aluminum strip supplier, Haomei Aluminum can provide customized materials according to your technical requirements and application standards.
FAQ about Transformer Aluminum Strip
Which aluminum alloys are used for transformer winding?
Common alloys include 1050, 1060, 1070, and 1350 aluminum strip. These grades offer high electrical conductivity and stable performance, making them suitable for transformer winding applications.
What is the difference between 1060 and 1350 transformer aluminum strip?
1060 aluminum strip offers good conductivity and excellent formability, making it widely used in general transformer applications. 1350 aluminum strip is an electrical-grade material with higher conductivity, suitable for applications requiring improved electrical performance.
Can aluminum strip replace copper strip in transformer winding?
Yes, in many transformer designs, aluminum strip can replace copper strip. Aluminum provides lower density and better cost efficiency. However, final selection depends on design requirements, conductivity level, and operating conditions.
What thickness is used for transformer aluminum strip?
Common thickness ranges from 0.2 mm to 3.0 mm. The exact specification depends on transformer capacity, winding structure, and customer technical requirements.
Can you provide custom width aluminum strip for transformer winding?
Yes, Haomei Aluminum can provide custom slit widths based on drawings or technical specifications, including thickness, coil weight, and packaging requirements.
What are the surface requirements for transformer aluminum strip?
The surface must be clean, smooth, and free from scratches, oil stains, oxidation, and defects. High surface quality helps protect insulation materials during transformer winding.
How is transformer aluminum strip packaged for export?
Packaging typically includes moisture-proof paper, plastic film wrapping, wooden pallets, or wooden cases. Export-standard packaging ensures safe transportation for international delivery.