A family heritage. A global ambition.
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 for the iron and steel industry — every batch, every shipment.
From Magna Flux to GRAPH-HEX®
Founded by Henry Seeboth in 1962, Larpen began as a supplier of non-destructive testing equipment. In 1986 we began processing graphite in Kewaskum, WI — a pivotal shift into manufacturing.
In 2000 we launched the GRAPH-HEX® brand, a complete line of high-purity recarburizers. By 2005 Larpen was the leading supplier of carbon products to the iron and steel industry in North America. Today, integrated into the Unimetal Group, we combine that family heritage with truly global expertise.
What drives us forward.
Mission
Provide our customers with the best quality, price, and service — exceeding their expectations every single day.
Vision
Raise the standards of the metals industry through carbon solutions with superior quality, continuous innovation, and sustainable impact.
Values
Personal service, ISO-driven consistency, on-time delivery, competitive pricing, and continuous improvement.
Six decades of milestones.
- 1962–1985
Founding & Early Years
Henry Seeboth founds Larpen Supply Co, Inc, focused on Magna Flux and non-destructive testing equipment, then expands into foundry supply distribution.
- 1986
Graphite Processing Begins
Larpen Supply Co. initiates graphite processing at a facility in Kewaskum, WI — the pivotal shift into manufacturing.
- 1993
Becomes Larpen Metallurgical Service
Henry Seeboth retires; rebranding to LMS signals a strategic shift toward metallurgical products and services.
- 1996
Expansion to Hartford
A new 50,000 sq. ft. manufacturing facility is built in Hartford, WI to meet North American demand.
- 2000
Introduction of GRAPH-HEX®
Launch of GRAPH-HEX®, a flagship line of graphite products for the metal casting industry.
- 2001
North American Distributor Network
A continental distributor network expands reach and improves product distribution.
- 2002
ISO Certification
Larpen achieves ISO 9001:2000 registration under the new QS 9000 Standard.
- 2003
Ownership Transition
Pat Seeboth retires; Tim Reynolds assumes sole ownership, beginning a new era.
- 2005
Leading Carbon Supplier
Larpen emerges as the leading supplier of carbon products to the iron and steel industry in North America.
- 2006
Hartford Expansion
A 25,000 sq. ft. addition brings Hartford's total manufacturing space to 75,000 sq. ft.
- 2007
Houston Facility Opens
A 100,000 sq. ft. manufacturing facility opens in Galena Park, TX to better serve the Mexican market.
- 2012
China Operations
A new manufacturing facility opens in China to market GRAPH-HEX® globally.
- 2013
Mulga, Alabama
A new production facility in Mulga, AL completes the network for southeastern U.S. demand.
- Today
Unimetal Group
Integrated into the Unimetal Group, combining family heritage with global technical expertise.
Hartford, Wisconsin
1111 Western Drive · Hartford, WI 53027 · USA
Certified processes. Responsible production.
- ISO 9001:2008 certified quality management system
- Rigorous in-house laboratory testing and validation
- Environmental responsibility aligned with global ESG standards
- Employee and customer safety at every operational level
- Continuous improvement embedded in Unimetal Group governance
