X0508 4 2026-01-22 0 0001003078 MSC INDUSTRIAL DIRECT CO INC MSM 0001754267 Aarnes Robert B C/O MSC INDUSTRIAL DIRECT CO., INC. 515 BROADHOLLOW ROAD MELVILLE NY 11747 1 0 0 0 0 Class A Common Stock, $0.001 par value 2026-01-22 4 M 0 799 0 A 799 D Class A Common Stock, $0.001 par value 2026-01-22 4 M 0 24 0 A 823 D Restricted Stock Units (RSU) 2026-01-22 4 M 0 799 0 D Class A Common Stock, $0.001 par value 799 799 D Dividend Equivalent Units 2026-01-22 4 M 0 24 0 D Class A Common Stock, $0.001 par value 24 25 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. 1,598 RSUs were granted on January 22, 2025. 799 RSUs vested on January 22, 2026. 799 RSUs vest on January 22, 2027, provided that the Reporting Person continues to serve as Outside Director through the applicable vesting date. The vested shares will be delivered to the Reporting Person upon vesting. Includes 17.818 dividend equivalent units accrued on April 23, 2025, 15.676 dividend equivalent units accrued on July 23, 2025, and 15.888 dividend equivalent units accrued on November 26, 2025 with respect to the outstanding awards of restricted stock units (RSUs). Such dividend equivalent units vest at the same time(s) as the underlying RSUs and represent a contingent right to receive one share of Common Stock. /s/ Robert B. Aarnes 2026-01-26