Products & Capabilities

Custom Magnetic Components for Production Applications

Toroidal inductors, bobbin-wound coils, current sensing transformers, and power transformers. Wound to your drawings on ferrite, silicon-iron, and 1J85 permalloy cores. Wire gauges from 18 to 34 AWG. Turn counts from 200 to 1,500. Every unit tested. Every order RoHS compliant.

Product Lines

What We Build

Four core product categories, each manufactured to your exact specifications. Click through for detailed technical information on each.

Inductors

Custom Inductors

Toroidal and bobbin-wound inductors on ferrite and silicon-iron cores. 200 to 1,500 turns of copper or nickel magnet wire. DCR tolerance to ±5%. Filter chokes, power inductors, and current sensing coils for production applications.

View inductor capabilities →
Transformers

Custom Transformers

Current sensing transformers on high-permeability 1J85 cores. Power transformers on silicon-iron and ferrite. Isolation transformers for medical and industrial safety applications. Designed for your circuit requirements.

View transformer capabilities →
Materials

Core Materials

Ferrite cores for high-frequency switching applications. Grain-oriented 3% silicon-iron for power-frequency inductors and transformers. 1J85 permalloy for high-permeability current sensing. Each material selected for your operating conditions.

Explore core materials →
Materials

Wire Types

Copper magnet wire in 18, 26, and 34 AWG with single-coat enamel insulation rated to 155°C (NEMA MW80-C). Nickel wire for specialized sensing applications. SN100 lead-free solder termination on all assemblies.

Explore wire types →

Technical Specifications

Full Capability Range

These are the materials, dimensions, and tolerances we work with across all product lines. If your spec falls outside these ranges, send it to us. We source and qualify new materials regularly.

Parameter Range / Options Notes
Wire Gauges 18, 26, 34 AWG Copper and nickel magnet wire
Wire Insulation Single-coat enamel, 155°C NEMA MW80-C rated
Core Materials Ferrite, Silicon-Iron, 1J85 (Permalloy) Grain-oriented 3% silicon-iron available
Core Sizes (OD) 0.800" to 2.250" 20.32 mm to 57.15 mm
Core Sizes (ID) 0.551" to 1.750" 14.00 mm to 44.45 mm
Core Height 0.256" to 0.500" 6.50 mm to 12.70 mm
Turn Counts 200 to 1,500 Multi-lap winding for high turn counts
DCR Range 0.320 to 39.15 ohms Measured at room temperature
DCR Tolerance ±5% to ±15% Tighter tolerances available on request
Winding Types Toroidal, Bobbin-Wound Even distribution, consistent tension
Core Coatings Epoxy, Powder Coat Custom coating thickness available
Core Tape Yellow Mylar (3M Type 74) Applied before and/or after winding
Solder SN100 (Lead-Free) Lead-free tin termination
Compliance RoHS Compliant All materials and processes

At a Glance

Capability Ranges

Wire Gauge
18 to 34 AWG
Core OD
0.8" to 2.25"
Turn Count
200 to 1,500
DCR Range
0.32 to 39.15 Ω
DCR Tolerance
±5% to ±15%
Core Height
0.256" to 0.500"
Production Run
1K to 100K units
Lead Time (Repeat)
2 to 3 weeks

Materials

Core Materials and Wire Types

The right core material and wire selection determine how your component performs under load. We match materials to your application requirements.

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Ferrite Cores

High-frequency switching applications. Permeability from 750 to 15,000. Available in toroidal geometries from 0.878" to 1.424" ID. Ideal for EMI suppression, common mode chokes, and high-frequency power conversion.

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Silicon-Iron Cores

Grain-oriented 3% silicon-iron for power-frequency applications. Saturation flux density of 1.6 to 2.0 Tesla. Tape wound toroids in 7 mil and 9 mil strip thicknesses. Epoxy and powder coat finishes available.

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1J85 Permalloy Cores

High-permeability nickel-iron alloy for current sensing applications. Permeability exceeding 100,000. Precision epoxy coated. The core material behind accurate current measurement across industrial power monitoring systems.

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Copper Magnet Wire

Available in 18, 26, and 34 AWG. Single-coat enamel insulation rated to 155°C per NEMA MW80-C. 18 AWG for high-current bobbin windings. 34 AWG for high-turn-count toroidal coils.

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Nickel Wire

34 AWG nickel magnet wire for specialized sensing and instrumentation applications. Used in high-permeability toroidal assemblies where copper wire characteristics affect measurement accuracy.

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Tape and Coatings

Yellow Mylar insulation tape (3M Type 74, 1/2" width). Epoxy core coatings at 0.015" thickness. Powder coat finishes for tape-wound toroids. SN100 lead-free solder for all lead tinning.

Production

1,000 to 100,000 Units Per Run

Our production facility runs toroidal winding, bobbin winding, lead cutting, tinning, taping, and final inspection under one roof. Mixed SKUs in a single batch. Prototypes and first articles alongside full production orders.

First orders typically deliver in 6 to 8 weeks from sample approval. Repeat orders ship in 2 to 3 weeks. Your drawings stay on file for fast reorders.

First Order

6 to 8 weeks

Repeat Orders

2 to 3 weeks

Run Size

1K to 100K

Mixed SKUs

Yes

Production batch of custom inductors ready for quality inspection

Quality

Every Unit Tested Before It Ships

DCR measured at room temperature with a micro-ohmmeter. Inductance verified on an LCR meter at the specified test frequency. Hi-pot (dielectric withstand) testing on coupled inductors and transformers per IEC 60950. Visual and mechanical inspection for winding distribution, insulation integrity, lead length, tinning quality, and overall dimensions.

  • DCR measurement on every unit
  • Inductance verification at specified frequency
  • Hi-pot testing per IEC 60950
  • Visual and dimensional inspection
  • Full test data included with every shipment
  • Certificate of conformance on every lot
  • Complete lot traceability
Quality inspection of toroidal inductor showing precision winding detail

Track Record

150,000+ Cores Delivered. 6 Product Lines. 0 Rejected Lots.

We supply NK Technologies in San Jose with custom toroidal inductors and bobbin-wound coils for their current sensor product line. Since April 2025, we have delivered across six active part numbers on ferrite, silicon-iron, and 1J85 cores.

Units Delivered

150,000+

Product Lines

6 Active

Rejection Rate

0%

Core Materials

Ferrite, Si-Fe, 1J85

Have a specification to discuss?

Send us your drawings or RFQ. We review every detail and respond within 24 hours with a quote and lead time.

Request a Quote
joe@ampmanufacturing.com 510-473-7714