<PAGE>

                                                                      EXHIBIT 24



                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 15th day of January,
1998.



                                        Richard G. Cline
                                       -----------------------------------
                                        Richard G. Cline
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 15th day of January,
1998.



                                        Robert J. Darnall
                                       --------------------------------------
                                        Robert J. Darnall
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 16th day of January,
1998.



                                        James A. Henderson
                                       ------------------------------------
                                        James A. Henderson
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 15th day of January,
1998.



                                        Neil S. Novich
                                       ---------------------------------------
                                        Neil S. Novich
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 18th day of January,
1998.



                                        Jerry K. Pearlman
                                       ---------------------------------------
                                        Jerry K. Pearlman
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 15th day of January,
1998.



                                        Donlad S. Perkins
                                       ------------------------------------
                                        Donald S. Perkins
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 15th day of January,
1998.



                                        Jean-Pierre Rosso
                                       -------------------------------------
                                        Jean-Pierre Rosso
<PAGE>

                               RYERSON TULL, INC.

                               POWER OF ATTORNEY



     KNOW ALL MEN BY THESE PRESENTS, that I, the undersigned, as a director
and(or) officer of Ryerson Tull, Inc., a Delaware corporation, do hereby
nominate, constitute and appoint Robert J. Darnall, Jay M. Gratz, Vicki L. Avril
and Charles B. Salowitz, or any one or more of them, my true and lawful
attorneys and agents to do any and all acts and things and execute any and all
instruments which said attorneys and agents, or any of them, may deem necessary
or advisable to enable said Ryerson Tull, Inc. to comply with the Securities
Exchange Act of 1934, as amended, and any requirements of the Securities and
Exchange Commission in respect thereof, in connection with the preparation and
filing of the Annual Report on Form 10-K of said Ryerson Tull, Inc. for the
fiscal year ended December 31, 1997, including specifically, but without
limitation thereof, full power and authority to sign my name as a director
and(or) officer of said Ryerson Tull, Inc. to said Annual Report on Form 10-K
and any amendment thereto, hereby ratifying and confirming all that said
attorneys and agents, or any of them, shall do or cause to be done by virtue
thereof.

     IN WITNESS WHEREOF, I have hereunto set my hand this 21st day of January,
1998.



                                        Ronald L. Thompson
                                       -----------------------------------
                                        Ronald L. Thompson