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Flat Magnet Wire
Space-saving, high-current rectangular magnet wire for power supplies, specialty motors, and toroidal transformers — custom-formed to your dimensions and insulation, made in the USA.
Rectangular Magnet Wire, Built to Your Spec
A space-saving profile, excellent heat dissipation, and high current capacity — tailored to your exact dimensions and insulation requirements for high-efficiency electromagnetic systems.
Magnet wire delivers efficient conductivity and reliable insulation for the coils, transformers, and motors at the heart of electrical systems. Bridgeport Magnetics’ Flat Magnet Wire was introduced in 2001 and has since gained wide acceptance among manufacturers of power supplies and specialty motors in many countries. The product covers wire sizes from 32 AWG (0.24 mm) up to 11 AWG (2.39 mm) in the round shape, with standard thickness-to-width ratios of 1:2, 1:2.5, 1:3, 1:3.5, and 1:4. All sizes are available on spools measuring 6″ OD × 3.5″ (10 lb).
Why Our Flat Magnet Wire Is Widely Renowned
Space-Saving Profile
The flat, rectangular cross-section packs more copper into less space, raising power density in compact coil and transformer designs.
Excellent Heat Dissipation
More surface area in contact with adjacent turns improves thermal performance and helps windings run cooler under load.
High Current Capacity
Greater conductor cross-section carries high current with low resistance — ideal for power supplies and high-efficiency systems.
Precision-Formed & Insulated
Each strand is precision-formed and insulated to hold structural integrity under mechanical and thermal stress.
Tested for Uniformity
Every run is tested for durability, conductivity, and winding uniformity so it performs predictably in your build.
Ideal for Toroidal Winding
Consistent bend radius, packing density, and insulation make flat wire especially effective in toroidal transformer winding.
Standard Sizes, Ratios & Spools
Need a ratio thinner than 1:4 or a non-standard dimension? We build to spec.
| Specification | Range / Standard |
|---|---|
| Wire size range | 32 AWG (0.24 mm) – 11 AWG (2.39 mm), round equivalent |
| Standard thickness-to-width ratios | 1:2, 1:2.5, 1:3, 1:3.5, 1:4 |
| Thinner ratios (> 1:4) | Available as Laminax foil — see below |
| Standard spool | 6″ OD × 3.5″ (10 lb) |
| Custom dimensions & insulation | Built to your specification — call for custom ratios |
| Origin | Manufactured in Shelton, Connecticut, USA |
Build a Complete Winding Solution
Laminax (EMI/RFI Shielding)
For ratios thinner than 1:4, our Laminax foil delivers ultra-thin copper in tape form for shielding and winding.
Explore Laminax →
Toroidal Transformers
Flat wire is purpose-built for our custom toroidal transformers — tight winding, high density, low loss.
View Toroidal Transformers →
Cores & Components
Pair custom wire with grain-oriented toroidal cores and components for a complete magnetic assembly.
View Cores & Components →
Frequently Asked Questions
What is flat (rectangular) magnet wire?
Flat magnet wire is insulated magnet wire with a rectangular cross-section instead of round. The flat profile packs more copper into a given space, improves heat dissipation, and winds tightly — raising power density in coils, transformers, and motors.
What sizes and ratios do you offer?
We offer round-equivalent sizes from 32 AWG (0.24 mm) to 11 AWG (2.39 mm), in standard thickness-to-width ratios of 1:2, 1:2.5, 1:3, 1:3.5, and 1:4. For ratios thinner than 1:4, see our Laminax foil products. Custom dimensions and insulation are available on request.
How is it supplied?
All standard sizes ship on spools measuring 6″ OD × 3.5″ (10 lb). Custom spooling can be discussed for production volumes.
Why choose flat wire over round magnet wire?
For the same conductor area, flat wire achieves higher packing density, better thermal contact between turns, and higher current capacity — which is why it’s preferred in compact, high-efficiency power supplies, specialty motors, and toroidal transformers.
Can you make custom ratios or insulation?
Yes. We precision-form and insulate each strand to your specification. Call (203) 954-0050 or email sales@bridgeportmagnetics.com for custom ratios, dimensions, or insulation systems.
Is it made in the USA?
Yes — our flat magnet wire is manufactured in Shelton, Connecticut.
Conductivity and durability your system demands.
Flat magnet wire in a range of sizes, ratios, and insulation systems — precision-formed and tested in Shelton, Connecticut. Custom ratios welcome.