1962–1985
Founding and Early Years
Henry Seeboth founded Larpen Supply Co., Inc., focusing on Magna Flux and non-destructive testing equipment, later expanding into the distribution of foundry supplies.
Larpen Metallurgical Service is the leading supplier of graphite products and carbon additives throughout North America. As an ISO 9001 certified company, we deliver consistent, high-quality results to the iron and steel industry in every batch, every shipment.

Founded by Henry Seeboth in 1962, Larpen began as a supplier of non-destructive testing equipment. In 1986 we started processing graphite in Kewaskum, WI — a decisive shift toward manufacturing.
In 2000 we launched the GRAPH-HEX® brand, a complete line of high-purity recarburizers. In 2005 Larpen became the leading supplier of carbon products to the iron and steel industry in North America. Today, integrated into the Unimetal Group, we combine this family heritage with truly global expertise.
To offer our customers the best quality, price, and service — exceeding their expectations every day.
Raising the standards of the metals industry through superior quality carbon solutions, continuous innovation, and sustainable impact.
Personalized service, ISO consistency, on-time delivery, competitive prices, and continuous improvement.
Henry Seeboth founded Larpen Supply Co., Inc., focusing on Magna Flux and non-destructive testing equipment, later expanding into the distribution of foundry supplies.
Larpen Supply Co. began processing graphite at a facility in Kewaskum, WI — a decisive shift toward manufacturing.
Henry Seeboth retired; the rebranding to LMS marked a strategic shift toward metallurgical products and services.
A new 4,645 m² facility was built in Hartford, WI to meet growing North American demand.
Pat Seeboth retired; Tim Reynolds assumed full ownership, beginning a new era for the company.
Larpen achieved ISO 9001:2000 registration under the new QS 9000 Standard.
A continent-wide distributor network expanded Larpen's reach and improved product distribution.
GRAPH-HEX® was launched as Larpen's flagship graphite product line for the metal casting industry.
Larpen emerged as a leading supplier of carbon products to the North American iron and steel industry.
A 2,323 m² expansion increased Hartford's total manufacturing space to 6,968 m².
A 9,290 m² facility opened in Galena Park, TX to better serve the Mexican market.
A new manufacturing facility opened in China to support the global commercialization of GRAPH-HEX®.
Now part of Unimetal Group, combining a family-business legacy with global technical expertise.
A new production facility in Mulga, AL completed the network serving demand across the Southeastern United States.