X0609 4 2026-10-03 0 0001003078 MSC INDUSTRIAL DIRECT CO INC MSM 0001947693 McIsaac Martina false C/O MSC INDUSTRIAL DIRECT CO., INC. 515 BROADHOLLOW ROAD MELVILLE NY 11747 0 1 0 0 President & CEO 0 Class A Common Stock, $0.001 par value 2026-10-03 4 M 0 1173 0 A 9444 D Class A Common Stock, $0.001 par value 2026-10-03 4 M 0 187.737 0 A 9632 D Class A Common Stock, $0.001 par value 2026-10-03 4 F 0 480.737 130.12 D 9151 D Restricted Stock Units (RSU) 2026-10-03 4 M 0 1173 0 D Class A Common Stock, $0.001 par value 1173 0 D Dividend Equivalent Units 2026-10-03 4 M 0 187.737 0 D Class A Common Stock, $0.001 par value 187.737 1477 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. 4,692 RSUs were granted on October 3, 2022. 1,173 RSUs vested on each of October 3, 2023, October 3, 2024, October 3, 2025, and October 3, 2026. Includes 283.096 dividend equivalent units accrued on November 26, 2025, 305.921 dividend equivalent units accrued on January 28, 2026, 266.932 dividend equivalent units accrued on April 22, 2026, and 204.560 dividend equivalent units accrued on July 22, 2026, with respect to 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/ Martina McIsaac 2026-10-06