Consent of Independent Registered Public Accounting Firm
We have issued our reports dated November 9, 2009 with respect to the consolidated financial
statements, schedules, and internal control over financial reporting included in the Annual Report
of Insteel Industries, Inc. on Form 10-K for the years ended October 3, 2009, September 27, 2008
and September 29, 2007. We hereby consent to the incorporation by reference of said reports in the
Registration Statements of Insteel Industries, Inc. on Forms S-8 (File No. 033-61887, File No.
033-61889, File No. 333-48011, File No 333-30934, and File No. 333-123325).
/s/ Grant Thornton LLP
Greensboro, North Carolina
November 9, 2009