X0508 4 2025-11-05 0 0001003078 MSC INDUSTRIAL DIRECT CO INC MSM 0001800680 Clark Gregory Haefele C/O MSC INDUSTRIAL DIRECT CO., INC. 515 BROADHOLLOW ROAD MELVILLE NY 11747 0 1 0 0 VP & Interim CFO 0 Class A Common Stock, $0.001 par value 2025-11-05 4 M 0 221 0 A 669 D Class A Common Stock, $0.001 par value 2025-11-05 4 M 0 35.619 0 A 705 D Class A Common Stock, $0.001 par value 2025-11-05 4 F 0 92.619 86.68 D 612 D Restricted Stock Units (RSU) 2025-11-05 4 M 0 221 0 D Class A Common Stock, $0.001 par value 221 0 D Dividend Equivalent Units 2025-11-05 4 M 0 35.619 0 D Class A Common Stock, $0.001 par value 35.619 87 D Each RSU represents a contingent right to receive one share of Common Stock. The dividend equivalent units accrued with respect to outstanding awards of restricted stock units (RSUs) and vest at the same time(s) as the underlying RSUs. Each dividend equivalent unit represents a contingent right to receive one share of Common Stock. Disposition of Class A Common Stock to the Issuer to cover tax withholding obligations arising from the vesting of RSUs and DEUs. 882 RSUs were granted on November 5, 2021. 220 RSUs vested on each of November 5, 2022 and November 5, 2023, and 221 RSUs vested on each of November 5, 2024 and November 5, 2025. /s/ Gregory Haefele Clark 2025-11-07