Who Are the Core Customers of SunCoke Energy Company?

Integrated steelmakers-notably Cleveland-Cliffs Inc. and United States Steel Corporation-are SunCoke Energy customers because blast-furnace operations demand consistent metallurgical coke tonnages and quality to maintain furnace stability; in 2025 SunCoke reported ~5.4 million tons of coke-related throughput across its plants and terminals supporting these buyers.

Foundry customers require specialized coke grades for iron casting and represent a niche but higher-margin segment; international steelmakers and commodity traders use SunCoke logistics and terminal services to move metallurgical coal and coke globally, accounting for a meaningful share of terminal throughput in 2025.

SunCoke primarily serves businesses and institutions-industrial buyers, procurement managers sourcing SunCoke coke, and utilities buying byproduct power; transactional buyers contract on multi-year supply agreements and spot purchases through terminals.

The core customer base remains steel producer customers-procurement at large integrated mills-driving roughly 70-80% of metallurgical coke volumes and the majority of revenue from coke sales and cokemaking services in 2025; investor questions about SunCoke Energy customer concentration focus on exposure to a few large buyers.

The core customers of SunCoke Energy are metallurgical coke customers in the Rust Belt-primarily steel producer customers in Indiana, Ohio, and Illinois. Proximity to these mills minimizes logistics costs and lets SunCoke integrate coke deliveries into mill blast-furnace schedules, supporting a large share of its domestic revenue.

Beyond the Midwest, demand is meaningful at the Convent Marine Terminal in Louisiana, where SunCoke facilitates coal and coke exports to trans-Atlantic and Asian markets. In 2025 the Convent channel remained active as global steel producers sought high-grade U.S. coking coal to blend with lower-quality regional ores.

SunCoke Energy customers are concentrated where the company has physical assets and logistics scale; its coke plants and terminals drive the largest portion of sales. In 2025, integrated U.S. steel mills accounted for the majority of tonnage sold and the largest single share of EBITDA from metallurgical coke sales.

Demand appears to be growing in export markets and among steel producer customers seeking U.S. high-grade coking coal blends; 2025 trade flows showed steady export volumes via Convent as Asian and European mills blended U.S. coke to optimize furnace efficiencies and reduce overall feedstock variability.

SunCoke Energy leverages port terminals, rail connections, and storage to move third-party thermal coal, iron ore, and liquids, capturing counter-cyclical volumes versus metallurgical coke; logistics fees and transshipment revenues added $45 million of segment contribution in 2025, broadening the SunCoke Energy customers set beyond steel producers.

About 90 percent of SunCoke core customer base-primarily steel producer customers and metallurgical coke customers-remains on long-term, multi-year contracts that extend into the late 2020s, ensuring predictable volumes and >60 percent of 2025 coke revenue tied to contracted tonnage.

Foundry coke expansion targets industrial end users beyond automotive and construction steel, increasing repeat demand and stickiness; long-term supply agreements and integrated logistics raised renewal rates for SunCoke Energy customers to an estimated 85 percent in 2025.

The strongest growth lever is disciplined capital allocation: capital spending prioritized maintenance of coke-making assets while allocating spare logistics capacity to higher-margin third-party handling, delivering consolidated adjusted EBITDA resilience and supporting opportunistic revenue from transactional buyers of SunCoke coke and services.