Below is a partial list of over 100 magnetic (inductor and transformer) suppliers. In general their catalog parts are of proprietary design where they share the electrically parameters they wish to share. In no cases or very rare cases do they note the materials or winding information to make the equivalent part elsewhere.
Even when one manufacturer copies another making an exact equivalent the core material and winding information is not provided.
In the majority of the cases when production volumes are in the hundreds or thousands presenting a build to print drawing of your magnetic design to any of these suppliers they will quote and be more competitive than their catalog parts.
Power Electronics Expert easily creates a new custom magnetic drawings noting all of the materials and methods to build any magnetic component as well as we can reverse engineer a catalog part creating a build to print drawing to be made by anyone.
3L Coils
ABC Taiwan Electronics Corp.
Abracon LLC
AEM Inc.
Aillen
Allied Components International
Amigis LLC
Arilitech Electronic Corp.
AW Coil
Bel Inc.
Bourns Inc.
Cal-Chip Electronics, Inc.
Central Technologies
Chemi-Con
Chipsen
CODACA
Coilcraft
Coilmx
CorePower Magnetics
Custom Magnetics
Delevan
Delta Electronics
East Electronics
Eaton
ECS Inc.
Enerdoor
Ferroxcube
Gowanda Electronics
HALO Electronics Inc.
Hobart Electronics
INPAQ Technology Co. Ltd
iNRCORE LLC
ISL Products International
ITG Electronics Inc.
Jaro Components Inc.
Johanson Technology Inc.
KEMET
Knowles Voltronics
KOA Speer Electronics Inc.
Kyocera AVX
Laird-Signal Integrity Products
Littlefuse Inc.
Luminmax Optoelectronic Technology
MACOM Technology Solutions
Max Echo
Mentech Technology Inc.
Meritek
Mini-Circuits
Monolithic Power Systems Inc.
Murata Electronics
Newava Technology Inc.
NIC Components Corp.
Ohmite
Ole Wolff Electronics Inc
Optical Zonu Corp.
Pacific Transformer
Panasonic Industry
Prem Magnetics Inc.
Premier Magnetics
Premo S.L.
Pulse Electronics
QST
Recom Power
Renco Electronics Inc.
SAGAMI ELEC
Samsung Electro-Mechanics
Schott Corp.
Schurter Inc.
Segue
Shenshen Sanlord Electronics Co Ltd.
Signal Transformer
Stackpole Electronics Inc.
Standex-Meder Electronics
Sumida America Components Inc.
Suntsu Electronics Inc.
Superworld Electronics Pte Ltd
Susumu
Tai-TECH Advanced Electronics Co Ltd
Taiyo Yuden
Telma Group OOC
Tamura
TDK
TE
Toko America Inc.
Traco Power
Triad Magnetics
TT Electronics
Vanguard Electronics
Venkel
Vicor Corp.
Viking Tech
Vishay
Walsin Technology Corp.
WEC
Wurth Elektronik
XFMRS
Yageo America
Zenith Tek Inc.
Zettler Magnetics