November 7, 2023

Boston Centerless Partners with May River Capital

Woburn, MA – November 7, 2023 – Boston Centerless, a Woburn, MA-based provider of precision ground bar materials and preparation services, today announced that it has partnered with May River Capital, a Midwest-based private equity firm focused on helping high-caliber industrial businesses grow and prosper. Terms of the transaction were not disclosed.

Founded in 1958 by Len Tamasi, Boston Centerless (BC) has established itself as a proven and trusted manufacturer and distributor of precision materials. BC provides high-quality, precision metal bar for medical, dental, aerospace, defense, and other mission-critical end market applications. For example, BC’s products are used to make spinal implants, cranial drills, surgical instruments, fuel injection parts, and fluid control components, all of which require precision materials.

Under the leadership of owner and CEO, Steve Tamasi, the Company has grown to approximately 135 employees serving over 650 customers globally across two locations in Woburn, Massachusetts and Fort Wayne, Indiana. Tamasi and the entire BC leadership team will continue to lead the organization in their current roles as well as retain a significant ownership stake in the Company.

“After careful evaluation of our growth objectives, our team is thrilled to team up with a partner in May River that is like-minded and aligned with us on both our strategic path forward and, equally as important, our cultural values,” said Tamasi. He went on to comment that, “this partnership will enable us to accelerate our growth initiatives and ultimately better serve our customers’ needs. Customers should expect the same great service and quality products from us going forward.”

Pat St. John, Principal of May River, said “May River is very pleased to be selected to partner with Steve Tamasi and the broader BC leadership team. We were immediately impressed by the level of talent and operational excellence that resides within the organization. The Tamasi family has built a stellar operation and we look forward to assisting the team in realizing BC’s full potential in the years to come.”

The timing of the news follows BC’s recent production facility expansion into Fort Wayne, Indiana. BC intends to continue its geographic footprint and capabilities expansion strategy going forward with the vision to continue delivering industry-leading quality and turnaround times to customers.

Bigelow LLC and Pierce Atwood LLP served as financial and legal counsel to Boston Centerless while Paul Hastings LLP served as legal counsel to May River.

About Boston Centerless

With 65 years of experience, Boston Centerless is a proven and trusted manufacturer and distributor of precision raw materials and preparation services. Boston Centerless serves customers all over the world in a variety of industries, including medical, dental, aerospace, and defense. For more information, please visit

About May River Capital

May River Capital is a Chicago-based private equity firm focused on investing in lower middle-market, industrial growth companies. May River Capital invests in high-quality industrial growth businesses, including advanced manufacturing, engineered products and instrumentation, specialized industrial services, and value-added industrial distribution services. For more information, please visit