Magnet Wire Introduction
Outer Diameter of Magnet Wire
International standards such as IEC categorize magnet wires based on specified outer diameter ranges. For insulation classification: IEC utilizes Grades 1, 2, 3, NEMA employs Single, Heavy, or Triple, GB 6109 adopts clasess 1, 2, 3, and JIS adopts Classes 0, 1, 2, 3. Manufacturers may impose stricter tolerances beyond these standards to optimize wound coil design and enhance electromagnetic performance in end products.
The outer diameter of magnet wire includes both the conductor and the paint film. However, when customers inquire about the ‘size’ of enameled wire, they typically mean the conductor diameter only.
LP Industry
LP Industry is one of China’s professional magnet wire manufacturers, suppliers, and distributors, backed by 30 years of exporting experience, mainly supplies square magnet wire
flat / rectangular magnet wire and round magnet wire.
Bare Wire Diameter Range
LP Industry specializes in magnet wire diameters
Magnet Copper Wire
Round type is starting with 0.016 mm, and going up to a diameter of 3.50 mm.
Rectangular: thickness(a) 0.8-10mm, width(b)2-22m
Square: thickness(width) / a (b) 0.45 – mm
Magnet Aluminum Wire
Round type is starting with 0.16 mm, and going up to a diameter of 8.50 mm.
Rectangular: thickness(a) 1.6-10mm, width(b)2-25mm
Square: thickness(width) / a (b) 1.2mm – 9.1mm
Beside the standardized diameters a big variety of special diameters is produced according to customer’s specification. Bare wire to lerancesare very important in magnet wire asthey have direct impact on the resistance what again determines the variance of the final coil resistance.
Technical Data by Size for Magnet Wire
What is magnet wire?
Magnet wire is a metallic conductor insulated with a varnish and generally used for electrical applications. Most times magnet wire is wound in different shapes of coils to generate magnetic force for motors, transformers, magnets etc. LP Industry produces over 30,000 different types of magnet wire with the most important differences of characteristics as follows:
Conductor Material for Magnet Wire
Copper is thestandard used conductor material for magnet wire with excellent conductivity and very good wind ability, which can be drawn to 0.01mm ultra-fine wire diameter. its conductivity ≥ 58 MS/m (IACS 100%). Magnet copper wire is mainly used for high-end motors, precision instruments, high-frequency transformers. Compared with aluminum wire, copper wire has high cost but best performance.
Aluminum is ligher than copper, density is only 30% of copper, with significant lightweight advantages, conductivity ≈ 35 MS/m (IACS 61%). Magnet aluminum wire is suitable for high voltage casin resin dry type transformer, and house applications, etc.
More conductor information
For special applications a wide variety of conductor materials for magnet wire, such as Brass, Silver, Nickel, Gold, Stainless Steel, or alloys of copper for special characteristics. LP Industry mainly provides magnet copper wire and magnet aluminum wire.
Spool Types for Magnet Wire
Spool types have to fit to the wire size. Finer magnet wire sizes are wound on smaller spools, while for heavy sizes of magnet wire, very large spools can be used. They are important for productivity as larger spools require less spool changes on the winding machines.
Magnet round wires from 1mm to 3.5mm typically use plastic reels (models PT-40, PT-60, PT-90, PT-120, PT-150, and PT-200), while wooden reels are used for diameters above 3.5mm. Magnet flat wires generally employ wooden reels. Customized reel options are also available.
Insulation Types for Magnet Wire
LP Industry offersawide range of different insulations. Polyurethane has the advantage of easy direct contacting by soldering,while Polyester insulations are more resistant against higher temperatures. Thin top coats as Nylon or Polyamidimide may improve certain desired characteristics like mechanical or chemical strength of the magnet wire.
Lubrication for Magnet Wire
A defined very low amount of lubrication-mostly special types of paraffin- is applied to achieve excellentwindability of the magnet wire in all winding processes without wire breaks.
Thermal Class of Magnet Wire
The thermal class of magnet wire indicates the maximum sustained temperature its insulation can withstand without degradation. LP Industry primarily supplies magnet wires in F-grade (155℃), H-grade (180℃), C-grade (200℃), and HC-grade (220℃), along with self-adhesive variants. Our factory also produces acetal-magnet wires rated at A-grade (105℃) and E-grade (120℃).
Magnet Wire Colors
The color of our magnet wire results from enamel coating applied over the conductor’s natural hue. Aluminum wire typically exhibits a brown or brown-black appearance, while copper wire develops brown-yellow to brown-red tones.
Our Production Line of Magnet Wire
LP Industry is a specialist in magnet aluminum wire, offering a comprehensive range of products distinguished by various magnet types and conductor materials.
Magnet Wire – Diameters for Aluminum:
Round type 1 mm-8.50 mm
Flat type: thickness 0.8 mm-10 mm, width: 1mm – 25mm
Square type: thickness(width) 1 mm-10 mm
Specifications for Magnet Wire
LP Industry produces magnet wires according to many different specifications.The most important worldwide used specification is IEC, besides NEMA in North America and JIS in Asia.
Polyvinyl Acetal
Polyvinyl acetal serves as conductor insulation in magnet wire primarily due to its excellent electrical insulation, mechanical strength, adhesion, and environmental resistance. While materials like polyester and polyamide-imide have replaced it in high-temperature applications (>130℃), it remains indispensable for standard applications. Through continuous modification, its applicability continues to expand, with typical temperature resistance ratings of 105℃ and 120℃
Polyesterimides
Polyesterimides offer superior high-temperature resistance but typically cannot be directly soldered in their base form (e.g., Estersol 180®). Modified versions such as Theic-Polyesterimides (e.g., Amidester 200®/210®) address this limitation while retaining thermal stability.
Polyamide-imides and Polyimide
Polyamide-imides and Polyimides deliver the highest thermal/chemical resistance, classified as Class 220 or Class 240 magnet wires in LP Industry’s portfolio.
Polyurethane
is a varnish which is easy for direct contacting by soldering, welding or crimping. Polyurethanes are available with Temperature Index 155 C (Polysol 155) and Temperature Index of 180 C (Polysol 180).
How to choose enamel insulation materials?
Main Products
Mainly provides materials of transformer winding: enameled wires, copper & aluminum foils, etc.
Enameled Aluminum Wire
Rectangular Type: thickness: 0.8--10mm, width: 2-25mm
Enameled Copper Wire
Rectangular Type: thickness: 0.8--10mm, width: 2-25mm
Paper Covered Wire
Shape: Round 1mm-7mm; Flat type: Width:3mm - 25mm; Thickness: 0.9mm - 10mm
Fiberglass Covered Wire
Shape: Round 0.071mm-5mm; Flat type: Width:2mm - 16mm; Thickness: 0.8mm - 5.6mm
Production Process for Magnet Wire
1.Raw Material Preparation
Select appropriate electrical round aluminum rods as raw materials, typically using grade 1A60 aluminum rods for optimal conductivity and formability.
2.Extrusion processing
The aluminum rod is cold-extruded to form bare aluminum flat wire, with strict dimensional control:
Fillet radius (R) tolerance: ≤30 μm
Conductor tolerance: ≤10 μm
3.Softening Treatment
The extruded bare aluminum flat wire undergoes electrical annealing to enhance ductility and elongation properties.
4.Cleaning Treatment
The bare aluminum flat wires undergo spray cleaning to remove surface impurities and oil residues, followed by wipe drying for optimal surface preparation.
5.Painting and Baking
The cleaned bare aluminum flat wires are transferred to a painting chamber for mold-based coating application. The painted wires then enter a curing oven, where controlled-temperature drying ensures uniform paint film solidification.
6.Cooling Process
The freshly enameled wires exiting the curing oven undergo rapid cooling to achieve optimal paint film properties. Forced air convection is employed to precisely control the cooling rate, ensuring proper cross-linking of the polymer matrix while maintaining required mechanical strength and surface hardness specifications.
7.Lubrication and Winding Process
Following cooling, the enameled aluminum flat wire undergoes precision lubrication treatment before being wound onto bobbins. The computer-controlled winding system ensures uniform tension and precise layering, achieving optimal packing density while maintaining insulation integrity. Critical winding parameters including tension (typically 2-5N) and traverse speed are continuously monitored to guarantee consistent coil formation.
8.Quality Assurance Protocol
All production batches undergo comprehensive quality verification through。All test parameters strictly adhere to IEC 60317-30 and GB/T 6109.1 standards, with automated optical inspection systems providing 100% dimensional verification and statistical process control maintaining CpK≥1.67 for all critical characteristics.
Magnet Wire Applications
power transformers Electrical Motors New energy vehicle charging pile Cleaning energy
Technical Data
Technical Data for Enamelled Wire by Size
The most important technical parameters of magnet wire are determined by its resistance and outer diameter. Key specifications of magnet wire include conductor diameter, thermal class, application, weight, packaging, and enamel film properties. Different standards define these values differently. The three major international standards for enamelled wire are categorized by size: IEC (International Electrotechnical Commission) serves as the harmonized global baseline standard, while NEMA (North America), GB (China), and JIS (Japan) retain additional legacy requirements in their respective national standards.