Nikon SLM Sets Co-President Structure as Sam O’Leary Moves to Supervisory Board

Nikon SLM Solutions is dividing its leadership responsibilities between two co-presidents for day-to-day operations and Sam O’Leary, who will move from chief executive to a seat on the company’s Supervisory Board. The transition is planned for Q4, 2026. The timing places the management change alongside the planned Formnext launch of MACHX, which the company has identified as a focus for its customer work.

Jan-Niklas Thielmann, currently Chief Financial and Administration Officer, and Simone Castellani, currently Chief Technology and Engineering Officer, will become Co-Presidents and join the Management Board. Their remit will cover daily operations. O’Leary will remain involved in strategic guidance and customer and partner support, while Hamid Zarringhalam will continue overseeing Nikon SLM as part of Nikon Advanced Manufacturing.

That division gives the company’s operating leaders responsibility for execution while retaining O’Leary’s involvement in a supervisory and advisory capacity. The roles also bring finance and administration leadership together with technology and engineering leadership at the top of the operating structure. The source does not describe changes to individual teams, reporting lines below the Management Board, or the company’s product plans beyond the focus on MACHX.

Operational continuity alongside MACHX

For customers evaluating industrial additive manufacturing equipment, leadership changes matter mainly through their potential effect on product delivery, technical support and longer-term commitments. Nikon SLM’s stated arrangement keeps O’Leary connected to strategy and customer relationships while assigning daily management to Thielmann and Castellani. Zarringhalam’s continued oversight preserves the company’s position within Nikon Advanced Manufacturing.

The company describes the transition as continuity and says it comes from a position of strength. Those are its characterizations; the announcement gives no financial measures or operating data to quantify the business’s condition. The concrete details are the appointments, the timing and the stated allocation of responsibilities.

Thielmann said the pair’s priorities remain customers, employees and the technology they build. Castellani tied the immediate focus to MACHX and to helping customers turn ambitious concepts into repeatable production. That emphasis points to a familiar challenge in industrial 3D printing: a machine’s value depends not only on producing a part, but on enabling a process that can be repeated reliably in a production setting. The company has not provided technical specifications, application data or qualification results for MACHX in this leadership update, so its production capabilities cannot be assessed from these details alone.

Formnext provides the stated venue for MACHX’s introduction. Zarringhalam described the launch as two weeks away when commenting on the leadership change, but no calendar date for that comment is supplied here. The company’s timeline therefore identifies the event and the planned sequence without establishing a more precise launch date in this account.

Roles and responsibilities

Thielmann and Castellani bring different current portfolios into the co-president roles: Thielmann leads finance and administration, while Castellani leads technology and engineering. Their joint appointment places those functions in a shared operating leadership structure. The company has not detailed how the co-presidents will divide decisions or whether either will take responsibility for specific markets, product lines or customer groups.

O’Leary said he would remain closely involved through the Supervisory Board and continue supporting the company and its customers. He also described the transition as a suitable moment to pursue an interest in sports and entertainment. His move is therefore presented as a change in executive role rather than a departure from the organization.

For teams working with Nikon SLM, the practical points to watch are whether the named customer focus carries through the transition and what technical and production information accompanies MACHX’s introduction. The leadership announcement sets out who will run daily operations and who will remain involved in oversight; product performance and customer impact will depend on information beyond the appointments themselves.

Nikon SLM Solutions is part of Nikon Advanced Manufacturing, which Zarringhalam leads. Nikon SLM’s new structure is scheduled to take effect during Q4, 2026, with Thielmann and Castellani leading daily operations and O’Leary continuing in a supervisory role.