X0508 4 2023-08-31 0000861884 RELIANCE STEEL & ALUMINUM CO RS 0001256541 Lewis Karla R 16100 N. 71ST STREET, SUITE 400 SCOTTSDALE AZ 85254 1 1 0 0 President, CEO 0 Common Stock 2023-08-31 4 S 0 9815 284.14 D 111443 D Common Stock 2023-08-31 4 S 0 185 284.51 D 111258 D Common Stock 2023-09-01 4 S 0 4849 285.63 D 106409 D Common Stock 2023-09-01 4 S 0 14271 286.28 D 92138 D Common Stock 2023-09-01 4 S 0 2477 287.17 D 89661 D Common Stock 2023-09-01 4 S 0 403 288.30 D 89258 D Common Stock 7148 I Held by Trustee of Reliance Steel & Aluminum Co. Employee Stock Ownership Plan Common Stock 205 I Held by Trustee of Reliance Steel & Aluminum Co. 401(k) Plan The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $283.50 to $284.48. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $284.49 to $284.52. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $284.86 to $285.85. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $285.86 to $286.82. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $286.86 to $287.51. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. The price reported represents the weighted average sale price of the shares disposed of. The actual sale prices ranged from $288.25 to $288.30. The Reporting Person has provided to the Issuer, and hereby undertakes to provide upon request by the U.S. Securities and Exchange Commission staff or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. /s/ Karla R. Lewis by William A. Smith II as her Attorney-in-Fact 2023-09-01