Exhibit 4.2

Execution Version

JOSEPH T. RYERSON & SON, INC.,

as Issuer,

THE GUARANTORS PARTY HERETO,

and

WELLS FARGO BANK, NATIONAL ASSOCIATION,

as Trustee

Fourth Supplemental Indenture

Dated as of May 24, 2016

9% Senior Secured Notes due 2017

FOURTH SUPPLEMENTAL INDENTURE

FOURTH SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of May 24, 2016, by and among JOSEPH T. RYERSON & SON, INC., a Delaware corporation (the “Issuer”), the GUARANTORS (as defined herein) and WELLS FARGO BANK, NATIONAL ASSOCIATION (the “Trustee”), as Trustee under the Indenture (as hereinafter defined).

WHEREAS, the Issuer, the Guarantors and the Trustee have as of October 10, 2012 entered into an Indenture, as supplemented by (i) a Supplemental Indenture, dated as of December 30, 2014, by and among the Issuer, the Guarantors party thereto and the Trustee, (ii) a Second Supplemental Indenture, dated as of January 21, 2015, by and among the Issuer, the Guarantors party thereto and the Trustee and (iii) a Third Supplemental Indenture, dated as of October 14, 2015, by and among the Issuer, the Guarantors party thereto and the Trustee (as supplemented, the “Indenture”), providing for the issuance by the Issuer from time to time of its 9% Senior Secured Notes due 2017 (the “Notes”);

WHEREAS, Section 9.2 of the Indenture provides, among other things, that the Issuer, the Guarantors and the Trustee, with the consent of the Holders of not less than a majority in aggregate principal amount of the Notes, may enter into one or more supplemental indentures for the purpose of adding provisions to or changing or eliminating certain of the provisions of the Indenture;

WHEREAS, this Supplemental Indenture has not resulted in a material modification of the Notes for Foreign Account Tax Compliance Act (FATCA) purposes;

WHEREAS, the Issuer has received the written consents of the Holders of a majority of the aggregate principal amount of the Notes to amend the Indenture as provided herein and enter into this Supplemental Indenture;

WHEREAS, the Issuer represents that the consents of the Holders of a majority of the aggregate principal amount of the Notes is sufficient to effect the amendments contained herein;

WHEREAS, the Issuer and the Guarantors desire to enter into this Supplemental Indenture, and has duly authorized the execution and delivery of this Supplemental Indenture to modify the Indenture;

WHEREAS, concurrent with the execution hereof, the Issuer has delivered to the Trustee an Officers’ Certificate and has caused its counsel to deliver to the Trustee an Opinion of Counsel; and

WHEREAS, all conditions and requirements of the Indenture necessary to make this Supplemental Indenture a valid, binding and legal instrument in accordance with its terms have been performed and fulfilled by the parties hereto and the execution and delivery thereof have been in all respects duly authorized by the parties hereto.

NOW, THEREFORE:

For and in consideration of the mutual premises and agreements herein contained, the Issuer, the Guarantors and the Trustee covenant and agree, for the equal and proportionate benefit of all Holders of the Notes, as follows:

ARTICLE I.

EFFECTIVENESS AND EFFECT

Section 1.1 Effectiveness and Effect.

This Supplemental Indenture shall take effect on the date hereof, provided, however, that the amendments provided for in Article Two hereof shall only become operative if an aggregate principal amount of the Notes exceeding 50% of the aggregate principal amount of the Notes is accepted by the Issuer for payment on the Early Settlement Date (as defined in that certain Offer to Purchase and Consent Solicitation Statement of the Issuer, dated May 10, 2016), and such amendments provided for in Article Two hereof shall have no force or effect prior to the operative time specified in this Section 1.1. Subject to the foregoing, the provisions set forth in this Supplemental Indenture shall be deemed to be, and shall be construed as part of, the Indenture. All references to the Indenture in the Indenture or in any other agreement, document or instrument delivered in connection therewith or pursuant thereto shall be deemed to refer to the Indenture as amended by this Supplemental Indenture. Except as amended hereby, the Indenture shall remain in full force and effect.

ARTICLE II.

AMENDMENT OF THE INDENTURE

Section 2.1 Deletion of Definitions and Related References

Section 101 of the Indenture is hereby amended to delete in their entirety all terms and their respective definitions for which all references are eliminated in the Indenture as a result of the amendments set forth in Section 2.2 of this Supplemental Indenture.

Section 2.2 Amendments to Indenture.

Section 4.3 (Provision of Financial Information);

Section 4.5 (Taxes);

Section 4.6 (Stay, Extension and Usury Laws);

Section 4.7 (Limitation on Restricted Payments);

Section 4.8 (Limitation on Dividends and Other Payments Affecting Restricted Subsidiaries);

Section 4.9 (Limitation on Incurrence of Debt);

Section 4.10 (Limitation on Asset Sales);

Section 4.11 (Limitation on Transactions with Affiliates);

Section 4.12 (Limitation on Liens);

Section 4.14 (Offer to Purchase Upon Change of Control);

Section 4.17 (Business Activities);

Section 4.19 (Impairment of Security Interests);

Section 4.20 (Additional Note Guarantees);

Section 4.21 (Limitation on Creation of Unrestricted Subsidiaries);

Section 4.23 (Further Assurances);

Section 4.24 (Maintenance of Properties; Insurance; Books and Records);

Section 5.1 (Consolidation, Merger, Conveyance, Transfer or Lease); and

Section 6.1(4), (5), (6), (7), (8), (9) (Events of Default).

ARTICLE III.

MISCELLANEOUS

Section 3.1 Counterparts.

This Supplemental Indenture may be executed in counterparts, each of which when so executed shall be deemed to be an original, but all such counterparts shall together constitute one and the same instrument.

Section 3.2 Severability.

In the event that any provision in this Supplemental Indenture shall be held to be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

Section 3.3 Headings.

The article and section headings herein are for convenience only and shall not affect the construction hereof.

Section 3.4 Successors and Assigns.

Any covenants and agreements in this Supplemental Indenture by the Issuer and the Trustee shall bind their successors and assigns, whether so expressed or not.

Section 3.5 Governing Law.

THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK BUT WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.

Section 3.6 Effect of Supplemental Indenture.

Except as amended by this Supplemental Indenture, the terms and provisions of the Indenture shall remain in full force and effect.

Section 3.7 Trustee.

The Issuer hereby acknowledges and agrees to comply with its reporting obligations under the Trust Indenture Act of 1939. The Trustee assumes no responsibility for the correctness of the recitals herein contained, which shall be taken as the statements of the Issuer, and the Trustee shall not be responsible or accountable in any way whatsoever for or with respect to the validity or execution or sufficiency of this Supplemental Indenture, and the Trustee makes no representation with respect thereto.

Section 3.8 Endorsement and Change of Form of Securities.

Any Securities authenticated and delivered after the close of business on the date that this Supplemental Indenture becomes effective may be affixed to, stamped, imprinted or otherwise legended by the Trustee, with a notation as follows:

“Effective as of May 24, 2016, certain restrictive covenants of the Indenture and certain of the Events of Default have been eliminated and permission for a notice of redemption to Holders whose Notes are to be redeemed to be provided at least three (3) days before a redemption date has been granted, as provided in the Fourth Supplemental Indenture, dated as of May 24, 2016. Reference is hereby made to said Fourth Supplemental Indenture, copies of which are on file with the Trustee, for a description of the amendments made therein.”

Section 3.9 Benefits of Supplemental Indenture.

Nothing contained in this Supplemental Indenture shall or shall be construed to confer upon any person other than a Holder of the Notes, the Issuer, the Guarantors and the Trustee any right or interest to avail itself or himself, as the case may be, of any benefit under any provision of the Indenture or the Supplemental Indenture.

Section 3.10 Definitions.

Capitalized terms used but not defined herein shall have the respective meanings ascribed to them in the Indenture.

[Signature page follows.]

IN WITNESS WHEREOF, the parties hereto have caused this Supplemental Indenture to be duly executed by their respective officers hereunto duly authorized, all as of the day and year first above written.

[Signature Page to Joseph T. Ryerson & Son, Inc. Fourth Supplemental Indenture]

[Signature Page to Joseph T. Ryerson & Son, Inc. Fourth Supplemental Indenture]

[Signature Page to Joseph T. Ryerson & Son, Inc. Fourth Supplemental Indenture]

[Signature Page to Joseph T. Ryerson & Son, Inc. Fourth Supplemental Indenture]

[Signature Page to Joseph T. Ryerson & Son, Inc. Fourth Supplemental Indenture]