X0508 4 2023-12-01 0001423221 Quanex Building Products CORP NX 0001251789 GRIFFITHS WILLIAM C 945 BUNKER HILL SUITE 900 HOUSTON TX 77024 1 1 Common Stock 2023-12-01 4 S 0 24108 31.2456 D 80915 D Common Stock 2023-12-04 4 S 0 28296 32.1978 D 52619 D The shares were sold pursuant to a Rule 10b5-1 preset diversification program previously adopted by the reporting person on March 15, 2023. The price reported in Column 4 is a weighted price. These shares were sold in multiple transactions at prices ranging from $31.00 to $31.45, inclusive. The reporting person undertakes to provide to Quanex Building Products Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. The price reported in Column 4 is a weighted price. These shares were sold in multiple transactions at prices ranging from $32.00 to $32.45, inclusive. The reporting person undertakes to provide to Quanex Building Products Corporation, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote. /s/ Paul B. Cornett, Power of Attorney 2023-12-05