Hertha Metals, a Conroe, Texas-based steel technology startup, has closed a $133.65 million Series A co-led by Khosla Ventures and Doerr Capital. The financing includes a $65 million equity investment from the U.S. government through the Department of Defense’s Industrial Base Analysis and Sustainment program in partnership with the Economic Defense Unit. Clean Energy Ventures, Pear VC, Gates Frontier, Niterra SUISO no MORI Fund via Global Brain, Toyota Ventures and Siemens Financial Services also participated.
Founded in 2022 by CEO Laureen Meroueh, Hertha develops Flex-HERS, a steelmaking technology designed to convert iron ore into iron or steel through a single-step process using natural gas or hydrogen. The company has demonstrated the technology at a continuous one-tonne-per-day scale at its pilot facility in Conroe.
Hertha said the Series A capital will finance construction of Hertha Chalyx, a planned facility with annual production capacity of 10,000 tonnes of steel-grade and magnet-grade high-purity iron. The project is intended to expand domestic production of high-purity iron used in rare-earth permanent magnets and other industrial applications.
According to the company, Flex-HERS can process different grades and forms of iron ore and can produce iron and steel at 25% lower production costs than conventional blast furnaces. Hertha also says the process can reduce emissions by 50% when using natural gas and by up to 98% when using hydrogen.
Hertha previously announced more than $17 million in funding in July 2025 from investors including Khosla Ventures, Breakthrough Energy Fellows, Pear VC and Clean Energy Ventures. That capital was used to build and demonstrate its pilot facility.
