Mike Sobieski

Diamond Heat Treat has agreed to be acquired by Calvert Street Capital Partners. Diamond Heat Treat is based in Rockford, Illinois. Diamond represents the initial investment in the strategy to build a leading thermal processing company focused on value-added services. Central to this strategy is identifying and bringing together leading businesses that share a focus on world-class safety, quality, service, and advanced technology.
Mike Sobieski, CEO of the thermal processing strategy, commented: “Diamond represents our initial investment and we are delighted to partner with the Diamond team. The company, founded in 1996, has a long and well-deserved reputation for quality and service. We want to thank Bill Akre, Dan Neiber and Bill Denning and acknowledge their accomplishments. They have built an excellent company, and their priority has been to continue the success of the business and provide opportunities for their people. We are honored to continue – and hopefully build upon – their legacy.”
John Hubbard, Chairman, remarked, “I am excited that Diamond is our first step in building a best-in-class company that offers a range of advanced technologies. I believe that there is a tremendous opportunity to offer specialized services to address the evolving technological challenges in the marketplace. We look forward to announcing future acquisitions.”
As announced previously, Calvert Street has partnered with leading executives to build a meaningful thermal processing business. The team, which includes Don Longenette and Lewis Lance in addition to Mike Sobieski and John Hubbard, consists of highly experienced individuals who have spent their careers in thermal processing. This team has complementary skill sets and will be responsible for the day-to-day activities of the thermal processing platform.
Calvert Street is a Baltimore, Maryland-based private equity firm focused on investing in industrial service businesses in the lower middle-market. Since its inception in 1995, Calvert Street has focused on partnering with skilled management teams of privately held businesses to drive profitable growth and organizational transformation. The thermal processing partnership builds upon Calvert Street’s experience in other high-value add industrial sectors, including testing and inspection and precision machining.