X0306 4 2023-03-01 0000861884 RELIANCE STEEL & ALUMINUM CO RS 0001488432 Koch Stephen Paul 16100 N. 71ST STREET, SUITE 400 SCOTTSDALE AZ 85254 0 1 0 0 Exec. VP, COO Common Stock 2023-03-01 4 A 0 3066 0 A 20276 D Common Stock 747 I Held by Trustee of Reliance Steel & Aluminum Co. Employee Stock Ownership Plan Common Stock 1090 I Held by Trustee of Reliance Steel & Aluminum Co. 401(k) Plan /s/ Stephen Paul Koch by William A. Smith II as his Attorney-in-Fact 2023-03-03