Exhibit 24

                                POWER OF ATTORNEY

                                  July 21, 2014

The undersigned hereby constitutes and appoints each of Mark S. Silver and Erich
Schnaufer, acting together or individually, his or her true and lawful
attorney-in fact to:

   1.   execute for and on behalf of the undersigned, in the undersigned's
        capacity as a director of Ryerson Holding Corporation, any statement
        or report, including any amendment to any statement or report,
        required to be filed with respect to the undersigned under Section 16
        of the Securities Exchange Act of 1934, as amended, and any rules,
        regulations and requirements thereunder, including without limitation
        any Form 3, 4 or 5 or 13G, and to file any of the same with the
        Securities and Exchange Commission and any other appropriate U.S.
        regulatory authorities;

   2.   do and perform any and all acts for and on behalf of the undersigned
        which may be necessary or desirable to complete the execution of any
        such Forms and the filing thereof with the United States Securities
        and Exchange Commission and any stock exchange or similar authority;
        and

   3.   take any other action of any type whatsoever in connection with the
        foregoing which, in the opinion of such attorney-in-fact, may be of
        benefit to, in the best interest of, or legally required by, the
        undersigned, it being understood that the documents executed by such
        attorney-in-fact on behalf of the undersigned pursuant to this power
        of attorney shall be in such form and shall contain such terms and
        conditions as such attorney-in-fact may approve in his or her
        discretion.

The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary or proper to be done in the exercise of any of the rights and powers
herein granted, with full power of substitution or revocation, hereby ratifying
and confirming all that such attorney-in-fact, or his or her substitute or
substitutes, shall lawfully do or cause to be done by virtue of this power of
attorney and the rights and powers herein granted. The undersigned acknowledges
that the foregoing attorneys-in-fact, in serving in such capacity at the request
of the undersigned, are not assuming any of the undersigned's responsibilities
to comply with the Securities Exchange Act of 1934, as amended.

This power of attorney shall continue in full force and effect until revoked in
writing by the undersigned or his or her attorney-in-fact.

        IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney
to be executed as of the date first written above.

                                        /s/ Kirk K. Calhoun
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                                                Kirk K. Calhoun