SCHEDULE 13D/A

AMTECH SYSTEMS INC

Common Stock, $0.01 Par Value Per Share · CUSIP: 032332504

Event date: 2025-02-13

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Piton Capital Partners LLCReported CIK 0001644342

  Shares: 600,000.00 · Class: 4.2%

• Cornice Fiduciary Management LLC, as Trustee under Trust Agreement dated December 23, 1989 FBO the issue of Jonathan D. SacklerReported CIK 0001760183

  Shares: 1,386,312.00 · Class: 9.7%

• Robert AverickReported CIK 0001343599

  Shares: 2,894,588.00 · Class: 20.2%

• M3C Holdings LLCReported CIK 0001595803

  Shares: 263,688.00 · Class: 1.8%

• OIH LLCReported CIK 0001651816

  Shares: 22,917.00 · Class: 0.2%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.