HarbisonWalker Data Breach Exposes Sensitive Financial Account Information

HarbisonWalker International Inc. (HWI), a U.S.-based company that makes and supplies heat-resistant materials for high-temperature industrial processes, has disclosed a data breach involving its internal network. The company, headquartered in Pittsburgh, Pennsylvania, is the largest supplier of refractory products and services in the United States and is part of the Calderys group.

The breach was disclosed to the Massachusetts Office of Consumer Affairs and Business Regulation on Sept. 22, 2026. The company's notification letters to affected individuals are also dated Sept. 22, 2026.

HWI identified suspicious activity on its internal network.

Upon learning of the suspicious activity, the company took steps to secure its network and investigate what had occurred. At this time, the key details such as the specific dates the incident took place or the particular method of attack involved remain undisclosed.

The types of personal information that may have been exposed include Social Security numbers and financial account information.

HarbisonWalker International's response to the breach

HWI is offering 24 months of complimentary credit monitoring and identity theft protection services through Experian IdentityWorks.

Affected individuals can enroll online at the Experian IdentityWorks enrollment page using the activation code included in their notification letter. Enrollment must be completed by Dec. 31, 2026.

For questions or assistance, affected individuals can call 1-833-575-2853, available Monday through Friday from 8 a.m. to 8 p.m. Central Time, excluding major U.S. holidays. Individuals may also write to HWI at 2000 Park Lane Drive, Suite 400, Pittsburgh, PA 15275.