Vacuumschmelze Brand Guidelines: Heraeus’s 1923 Hanau Spin-Off, Siemens Years & VAC Magnets

A laboratory idea at Heraeus.

Vacuumschmelze — German for “vacuum melting” — began as a laboratory process in Hanau, east of Frankfurt. The company says that in 1913 Wilhelm Rohn, head of the physical laboratory at the precious-metals firm W. C. Heraeus, developed a way of melting metals in a vacuum, aiming to replace costly platinum and rhodium with cheaper alloys such as chromium-nickel; the process was patented in 1918. German Wikipedia adds that the First World War delayed the work by about three years.

On 1 July 1923 Heraeus spun off its melting and processing department for base metals, with about 50 staff under Rohn, as Heraeus-Vacuumschmelze AG. The company’s centenary history, published in 2025, notes that Heraeus itself could by then look back on more than 250 years, its origins lying in a Hanau pharmacy. In 1927 the new firm developed MUMETALL, a soft magnetic nickel-iron alloy that it still makes and that is used for magnetic shielding, current sensors and transformers. From 1930 came NIVAROX, an alloy the company says is still used in mechanical watches, and by that year it held 84 German patents.

Siemens, the war and rebuilding.

In November 1933 Siemens & Halske took 81.5 per cent of the shares, after a long collaboration, according to the company and German Wikipedia; VAC then remained part of the Siemens group for more than 65 years. By 1939 the works covered 17,000 square metres and employed about 550 people.

The war years are part of that record. In the foreword to the centenary history, Vacuumschmelze: Eine Industriegeschichte, published by Deutsche Verlags-Anstalt in 2025 and written by historians together with chief executive Erik Eschen, Eschen thanks colleagues who had examined the company’s history under National Socialism in earlier decades — through VAC’s participation in German industry’s foundation initiative to compensate forced labour, the foundation “Remembrance, Responsibility and Future,” and in a chronicle for its 90th anniversary. The company says the Hanau plant was largely destroyed by the end of the war; a melting furnace and a small hot-rolling mill were running again eight weeks later, and German Wikipedia says the works were back in operation with 479 staff three years after the war.

Recovery came through new alloys. ULTRAPERM, a high-permeability soft magnetic alloy, followed from 1948, and in 1950 VAC took over a permanent-magnet plant in Berlin from Siemens & Halske. The company says that in the mid-1950s it supplied spring materials for more than 20 million watches a year, and that in 1969 it won a large order for superconductor for an experiment at CERN in Geneva. In 1973 it began samarium-cobalt magnets under the name VACOMAX; in 1977 it started work on amorphous metals, later sold as VITROVAC; and in the mid-1980s it launched neodymium-iron-boron magnets under the name VACODYM. The nanocrystalline alloy VITROPERM followed in the 1990s.

Design and documentation.

Rare-earth and magnet companies sell materials most people never see, so their pictures do a lot of the explaining. The usual opening image is the mine: an open pit cut in benches into red or ochre desert ground, haul trucks small against the terraces, and a wide sky above. It tells a viewer that the story starts with rock and with a particular place, which matters in a business where origin is part of the product.

The next scenes are inside the plant. Separation is slow chemistry, and companies often show it as long rows of mixer-settler tanks, pipework and walkways, or a rotating kiln seen from its end. The finished goods then appear as oxide powders in small dishes or heaps, often in soft pastel shades of pink, green, grey and cream, a quiet way to show that one ore becomes many separate elements.

Magnets bring the story to the customer. Silver blocks, rings and arcs stacked on a bench, or set into a cutaway of an electric motor or a wind-turbine generator, link the material to the products people know. Investor presentations add the periodic table, usually with the lanthanides picked out in a highlight colour, along with maps that trace the route from mine to separation plant to magnet factory.

The same visual vocabulary appears at trade gatherings, from the events of the Rare Earth Industry Association to the Magnetics conference, where stands and slides lean on the same few motifs: the pit, the plant, the powder and the magnet. For a designer, the category shows how a technical, slow-moving industry can be made legible through a short, repeated sequence of images rather than through slogans.

Investors, Hanau and South Carolina.

VAC built factories abroad from the 1990s. German Wikipedia dates its production sites in Malaysia to 1994, the United States to 1996, Slovakia to 1997, China to 2001 and Finland to 2005; the company dates its Shenyang business to approval in January 2001 and its Finnish magnet business to the purchase of Neorem Magnets in 2007. In 1999 Siemens sold VAC to the British Morgan Crucible company. Since then it has belonged to a series of investors, German Wikipedia says: One Equity Partners from 2005; the OM Group from August 2011, whose own takeover by Apollo Global Management brought VAC into Apollo’s portfolio; and, from October 2023, Ara Partners of Houston. Its superconductor business went to Bruker in 2003. The company says it employs almost 4,000 people, with Hanau as its main site.

Its newest plant is American. In December 2023 VAC’s US business, eVAC Magnetics, announced its first US production facility, on 85 acres in the Pocotaligo Industrial Park in Sumter County, South Carolina, Sumter’s economic development board reported. The company says eVAC began commercial magnet production there in 2025, including sintered magnets for car traction motors, and marked the plant with an opening ceremony on 15 July 2026; it gives the nameplate capacity as about 2,000 tonnes a year and the workforce as 130, with plans for 300.

VAC’s ownership may change again. On 23 June 2026 Energy Fuels, the US uranium and rare-earth producer, announced a definitive agreement to acquire VAC from Ara Partners. In its third-quarter results on 4 November 2026, Energy Fuels described the acquisition as pending, subject to regulatory approvals, and expected it to close in early 2027; it had not been completed at the time of writing.

For a design guide, Vacuumschmelze shows how a materials maker can turn a century of alloy names — MUMETALL, VACODYM, VITROPERM — into its working vocabulary. Compare Proterial, the former Hitachi Metals, another magnet maker with long industrial roots, and Energy Fuels, the company that has agreed to buy VAC. For this guide we use a steel blue and a copper with a sans, an unofficial interpretation; no product or logo is reproduced.

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