A. M. Castle & Co. Watch

from 10-K 4 pages Description of Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from 8-K 7 pages Supplemental Indenture and Amendment No. 2

from 8-K 160 pages Indenture, Dated as of March 27, 2020 Among A. M. Castle & Co., the Guarantors Party Hereto, Wilmington Savings Fund Society, Fsb, as Trustee and Wilmington Savings Fund Society, Fsb, as Collateral Agent 3.00% / 5.00% Convertible Senior Secured Pik Toggle Notes Due 2024

from S-4 161 pages N.A. Means Not Applicable. * This Cross Reference Table Is Not Part of the Indenture

from S-4 7 pages Supplemental Indenture and Amendment No. 2

from 10-K 4 pages Description of Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from 8-A12G 2 pages Number *0* Shares *0* See Reverse for Important Notices and Other Information A. M. Castle & Co. a Corporation Formed Under the Laws of the State of Maryland This Certifies That **Specimen** Is the Owner of **Zero (0)** Fully Paid and Nonassessable Shares of Common Stock, $0.01 Par Value Per Share, of A. M. Castle & Co. (The “Corporation”) Transferable on the Books of the Corporation by the Holder Hereof in Person or by Its Duly Authorized Attorney, Upon Surrender of This Certificate Properly Endorsed. This Certificate and the Shares Represented Hereby Are Issued and Shall Be Held Subject to All of the Provisions of the Charter of the Corporation (The “Charter”) and the Bylaws of the Corporation and Any Amendments or Supplements Thereto. in Witness Whereof, the Corporation Has Caused This Certificate to Be Executed on Its Behalf by Its Duly Authorized Officers. Dated: Steven W. Scheinkman, President and CEO Marec E. Edgar, Secretary

from 8-K 4 pages First Supplemental Indenture Dated December 8, 2016

from 8-K 4 pages Fourth Supplemental Indenture Dated December 8, 2016

from 8-K 6 pages Third Supplemental Indenture

from 8-K 13 pages Warrant This Warrant Will Be Void if Not Exercised Prior to 5:00 P.M., New York City Time, on June 8, 2018 Warrant to Purchase Shares of Common Stock of A.M. Castle & Co. Distribution Date: December 8, 2016

from 8-K 6 pages Second Supplemental Indenture

from 8-K 6 pages First Supplemental Indenture Dated May 16, 2016

from 8-K 119 pages A. M. Castle & Co. and Each of the Guarantors Party Hereto 5.25% Convertible Senior Secured Notes Due 2019 Indenture Dated as of May 19, 2016 U.S. Bank National Association Trustee and Collateral Agent

from 8-K 139 pages Indenture, Dated as of February 8, 2016, Among A. M. Castle & Co., the Guarantors Party Hereto, U.S. Bank National Association, as Trustee and U.S. Bank National Association, as Collateral Agent 12.750% Senior Secured Notes Due 2018 Ex-1

from 8-K 6 pages First Supplemental Indenture

from 8-K 2 pages Amendment No. 1 to Rights Agreement

from 8-K 50 pages Rights Agreement A. M. Castle & Co. and American Stock Transfer & Trust Company, LLC as Rights Agent, Dated as of August 31, 2012 Ex-7

from 8-K 115 pages A. M. Castle & Co. and Each of the Guarantors Party Hereto 7.00% Convertible Senior Notes Due 2017 Indenture Dated as of December 15, 2011 U.S. Bank National Association Trustee

from 8-K 129 pages Indenture, Dated as of December 15, 2011, Among A. M. Castle & Co., the Guarantors Party Hereto, U.S. Bank National Association, as Trustee and U.S. Bank National Association, as Collateral Agent 12.750% Senior Secured Notes Due 2016