(Editors Note; "Rochester Steel Treating Works" in Rochester, New York, USA is one of the oldest commercial heat treaters in the state and a long standing, profitable well run company. "The Monty Heat Treat News" helped facilitate this sale. More on this story and Diffusion Group of Companies to come-we promise you will find this interesting).

"Diffusion Group Expands U.S. Presence with Acquisition of Rochester Steel Treating Works

"RSTW has built something special over decades—our job is to protect that, strengthen it, and make sure it continues to grow for the next generation."— Tim Thompson, Diffusion Group

Rochester, NY – June 2026; The Diffusion Group of Companies has completed its acquisition of Rochester Steel Treating Works (RSTW), marking another step in the group's growth across North America and strengthening its position in the U.S. heat treating market.

RSTW is a long-established, highly respected operation with deep roots in the Rochester manufacturing community. Known for its quality, reliability, and technical capability, the business serves customers across aerospace, defense, automotive, tooling, and medical markets, supported by key industry certifications and a reputation built over decades.

The acquisition reflects Diffusion's long-term approach—identifying strong, well-run businesses and investing to support their continued success.

Diffusion would like to acknowledge and thank Gene and the Miller family for the trust they have placed in the group. The business they built stands as a testament to their commitment to quality, discipline, and customer service, and that legacy is not taken lightly.

"RSTW has built something you don't see every day—a combination of technical capability, strong culture, and customer trust," said Tim Thompson. "We have a lot of respect for what Gene and the Miller family created here, and we're proud they've trusted us to carry that forward."

Operational continuity remains a priority. RSTW's existing team and leadership remain in place, and there are no immediate changes to day-to-day operations. The focus is on reinforcing the business's foundation while investing thoughtfully in areas that improve quality, reliability, and long-term capability.

"What has made RSTW successful will continue," Thompson added. "Our focus is disciplined growth—practical investments, better systems, and giving the team the tools they need to succeed long term."

Looking ahead, Diffusion plans to leverage its combined technical knowledge and operational experience across the group to support RSTW's next phase of growth, expanding customer relationships, improving processes, and strengthening its position in key end markets.

The transaction also signals the group's continued expansion strategy.

"We're building a focused group of companies in this space," said Thompson. "RSTW is an important addition, and we're actively looking for other strong operations that fit what we're building."