Adams Magnetic Products, LLC

Permanent magnet and magnetic assembly manufacturer serving industrial, aerospace, and defense customers.

At a glance

Founded: 1950 — Founded by Leo Weinstein in Chicago, Illinois.
Headquarters: Elmhurst, Illinois, United States, with additional locations in Kentucky, New York, and Carlsbad, California
Ownership: Controlling stake acquired by High Street Capital in November 2023; the Lewis family retained a minority interest, and John Maisch became President.
Revenue: Not publicly disclosed. This company does not publish revenue and no named third party has published an estimate of it.
Privately held; no revenue figures disclosed.

Capacity

This company machines and assembles magnet blocks made elsewhere rather than pressing or sintering its own. Capacity in that work is set by what customers ask for in a given period rather than by installed press or furnace capacity, so it moves with the job mix. A single tonnage figure would describe one quarter's order book and misrepresent every other one. There is no figure here because there is no figure that would mean anything, not because one is being held back.

Narrative

Adams Magnetic Products, LLC is a privately held permanent-magnet and magnetic-assembly manufacturer founded in 1950 by Leo Weinstein in Chicago. It is headquartered in Elmhurst, Illinois, with additional locations in Kentucky, New York, and Carlsbad, California. In November 2023, High Street Capital acquired a controlling stake in the company; the Lewis family retained a minority interest, and John Maisch became President. The company's public materials are genuinely ambiguous about whether it produces raw magnet material or sources finished blocks for further processing, so this profile does not assert either model as fact. No country-of-origin or DFARS compliance statement was found on the company's public materials during research; this is reported as an absence rather than a confirmed negative.

Sources

Company website — Adams Magnetic Products, LLC (2026-09)

How this page is sourced

Everything here comes from public sources — company filings, annual reports, exchange announcements, government releases and trade press. Every figure is linked to the document it came from and carries the date that document was published, because a capacity number without a date is not a fact, it is a rumor with a decimal point.

What is deliberately absent: material nonpublic information. I have spent more than two decades in this industry and a good deal of what I know about these companies I learned under NDA. Those obligations do not expire and they do not bend for a website. Nothing I have been told in confidence appears here in any form, and nothing on this page — or missing from it — should be read as a signal about what I know privately. I hold NDAs absolutely. It is the reason clients tell me things.

Judgment is the other thing left out on purpose. This page reports what has been published and who published it. Whether a target is credible, whether a ramp will hold, whether a capacity figure survives contact with the plant behind it — that is the work I do for clients, and it does not belong in a free reference page.

Where public sources disagree, I say so rather than picking a winner. Where a figure has not been published, the field says so rather than carrying an estimate. An empty field is information too.

Public filings tell you what a company has said. Whether it holds up is a different question, and the one I get hired to answer.

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