Arnold Magnetic Technologies

Sintered samarium cobalt permanent magnets sold under the RECOMA brand, a small high-temperature niche in which Arnold is one of very few Western producers. Published grades run from RECOMA 18 to RECOMA 35E, with maximum operating temperatures up to 350 degrees Celsius for the high-temperature grades. The company also makes engineered magnetic assemblies, precision thin metals, flexible magnets and, since acquiring Ramco in 2021, electric motors, stators and rotors. End markets are aerospace and defense, general industrial, motorsport, oil and gas, medical and energy.

At a glance

Founded: 1895 — Arnold's published history dates the lineage to 1895, when Bion J. Arnold established the Arnold Electric Power Station Company; alnico production began under the Arnold Engineering Company in 1924. The present corporate name dates from 2005, when Audax Group acquired the business and renamed it. The samarium cobalt line specifically descends from Indiana General, whose rare-earth production the company dates to 1976.
Headquarters: Rochester, New York, United States
Ownership: Owned by Compass Diversified (NYSE: CODI), which acquired the business on 5 March 2012 for approximately USD 128.8 million and reported holding 98.0% of the stock on a primary basis, 82.8% fully diluted, at 31 December 2025. The prior owner was Audax Group, which had bought the business from Precision Castparts in 2005. Because the parent is SEC-registered, Arnold is one of very few magnet makers whose results are published.
Revenue: USD 151.0 million
Reported, full year 2025, ended 31 December 2025.
This is Compass Diversified's Arnold reporting segment, down from USD 171.8 million in 2024. It is broader than the magnet business: the segment also contains Ramco electric motors, Precision Thin Metals foil products and Flexmag flexible magnets. Rare earth magnet revenue alone is not broken out, and neither is revenue by site.
Source

Capacity

Each date below links to the document the figure came from. A capacity figure with no source is not on this page.

What	Figure	Status	As of
Sintered samarium cobalt, Lupfig, Switzerland, sold under the RECOMA brand. The company described this site as capacity-constrained with lead-time pressure in April 2026.	no tonnage published	Operating	Apr 2026
Fabrication of SmCo magnets at Rochester, New York, from block produced at Lupfig	no tonnage published	Operating	Sep 2026
Amata City Chonburi, Thailand — Phase 1, magnet finishing plus rotor and stator assemblies. The factory began operating in October 2024 and Phase 1 finishing capability was completed in March 2026.	no tonnage published	Operating	Apr 2026
Amata City Chonburi, Thailand — Phase 2, samarium cobalt production, shaping and finishing. Announced as a multi-million-dollar investment that the company says will double overall magnet production capacity.	full operational readiness stated for mid-2027; no tonnage published	Announced	Apr 2026
NdFeB production capacity at any Arnold site	not published	Announced	Sep 2026

Narrative

Arnold Magnetic Technologies traces its published lineage to 1895 and is headquartered in Rochester, New York. Compass Diversified acquired a controlling interest in March 2012 for about USD 128.8 million and reported owning 98.0 percent of the stock at the end of 2025; because that parent is SEC-registered, Arnold's segment results are public, at USD 151.0 million of net sales in 2025 against USD 171.8 million in 2024. The group's distinguishing position is in samarium cobalt, sold as RECOMA and produced at Lupfig, Switzerland, with some block shipped to Rochester for fabrication. A Thailand plant at Amata City Chonburi began operating in October 2024, and Arnold announced in April 2026 that samarium cobalt production there would reach full readiness by mid-2027.

Where public sources disagree

The scope of the Thailand increase is stated two ways by the company: a September 2025 release says the facility will more than double samarium cobalt output, while an April 2026 release says the expansion will double overall magnet production capacity. Different bases, different multipliers, and no tonnage attached to either.
Timing shifted too. The September 2025 release reads as near-term; the April 2026 release places samarium cobalt production in Phase 2 with full readiness only by mid-2027.
Three site capabilities recorded elsewhere could not be confirmed from any linkable source: samarium cobalt alloying at Rochester, NdFeB machining at Rochester, and block making in Thailand. What is published is narrower — Lupfig makes the SmCo, some block ships to Rochester for fabrication, and Thailand's step is described only as production, shaping and finishing.
No publicly announced US government or defense award to Arnold was found. The company emphasizes ITAR registration and DFARS compliance, which is a compliance posture rather than an award.
Samarium sourcing is described two ways: an undated company resource page describes a relationship with a rare earth mine in China, while a September 2025 release describes securing samarium sourcing outside China. The undated page appears to be the older statement but cannot be definitively sequenced.
Arnold's claims to be the market leader in high-performance samarium cobalt, and that no other Western supplier has such a robust SmCo supply chain, are the company's own and are recorded as claims.

Sources

Compass Diversified Q4 and full-year 2025 earnings release — Arnold segment net sales — Compass Diversified, filed with the SEC (2026-02-26)
Compass Diversified Form 10-K for 2025 — ownership percentage, acquisition date and price, segment scope — Compass Diversified, filed with the SEC (2026-02-27)
Strategic expansion for Thailand operations — Arnold Magnetic Technologies (2026-04-28)
Strategic investments and agreements to ensure continuity of critical rare earth materials supply — Arnold Magnetic Technologies (2025-09-23)
RECOMA samarium cobalt magnets — grades and maximum operating temperatures — Arnold Magnetic Technologies (accessed 2026-09-18)
Arnold Magnetic Technologies announces new USA Rare Earth agreement — non-exclusive mutual distribution — Arnold Magnetic Technologies via Business Wire (2026-03-23)
Acquisitions history — 1895 lineage, 1976 rare earth production start, 2005 renaming — Arnold Magnetic Technologies (2021-11)

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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