Flagship Line
GRAPH-HEX® Recarburizers
Over 50 high-purity carbon additives engineered to individual customer specifications, with sulfur as low as 0.02%.
SpecificationsNorth American Leader · Since 1962
Forging the
Future of Steel.
Six decades of metallurgical mastery. We deliver high-performance carbon and graphite solutions to the world's most demanding foundries and steel mills.
5 Units
USA & China Bases
ISO 9001
Certified Quality
50+
GRAPH-HEX® SKUs
Global
Supply Network
Product Excellence
Carbon engineered for performance.
High-purity carbon and graphite solutions engineered for extreme performance environments — from gray iron casting to integrated steel mills.
Steel & Iron
Machined Graphite
Crystalline graphite for injection applications and EAF processes, with consistent purity and rapid dissolution.
Specifications
Foundry
Pet Coke & Silicon Carbide
Low sulfur petroleum cokes (0.35–4.0% S) and Carbolon MA 90% silicon carbide for foundry chemistry.
Specifications
Our Commitments
The benchmarks of an industry leader.
A family-run business operating with global scale — combining personal service with the rigor of ISO-certified quality systems and continuous improvement.
60+ Years
Family-run heritage since 1962.
ISO 9001
Certified quality management.
Own Laboratory
In-house testing & validation.
5 Plants
USA + China manufacturing.
Global Logistics
On-time delivery worldwide.
Unimetal Group
Backed by global expertise.
Operational Footprint
See all units & China hub
Strategic North American Presence
Hartford Unit
1111 Western Dr, Hartford, WI 53027
Lemont Unit
12300 New Ave, Lockport, IL 60441
Mulga Unit
2530 Atwood Ferry Road, Mulga, AL 35118
Galena Park Unit
500 S Main St, Galena Park, TX 77547
Interactive Map · USA + China
Our Evolution
Full timeline →Six decades of metallurgical milestones.
1962
Founding
Henry Seeboth founds Larpen Supply Co.
1986
Graphite Processing
Operations expand into manufacturing.
2000
GRAPH-HEX®
Flagship recarburizer line launches.
2013
Global Reach
Mulga, AL completes the North American grid.
Let's Build Together
Ready to optimize your production?
Talk to our technical team about a custom carbon formulation engineered specifically for your foundry or steel mill.