1
 
                                                                      EXHIBIT 24
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ MICHAEL J. BIRCK
 
                                          --------------------------------------
                                          (signature)
 
                                          Michael J. Birck
 
                                          --------------------------------------
                                          (printed name)
   2
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ MARVIN D. BRAILSFORD
 
                                          --------------------------------------
                                          (signature)
 
                                          Marvin D. Brailsford
 
                                          --------------------------------------
                                          (printed name)
   3
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ SUSAN CROWN
 
                                          --------------------------------------
                                          (signature)
 
                                          Susan Crown
 
                                          --------------------------------------
                                          (printed name)
   4
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ H. RICHARD CROWTHER
 
                                          --------------------------------------
                                          (signature)
 
                                          H. Richard Crowther
 
                                          --------------------------------------
                                          (printed name)
   5
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ W. JAMES FARRELL
 
                                          --------------------------------------
                                          (signature)
 
                                          W. James Farrell
 
                                          --------------------------------------
                                          (printed name)
   6
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ L. RICHARD FLURY
 
                                          --------------------------------------
                                          (signature)
 
                                          L. Richard Flury
 
                                          --------------------------------------
                                          (printed name)
   7
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ ROBERT C. MCCORMACK
 
                                          --------------------------------------
                                          (signature)
 
                                          Robert C. McCormack
 
                                          --------------------------------------
                                          (printed name)
   8
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ PHILLIP B. ROONEY
 
                                          --------------------------------------
                                          (signature)
 
                                          Phillip B. Rooney
 
                                          --------------------------------------
                                          (printed name)
   9
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ HAROLD B. SMITH
 
                                          --------------------------------------
                                          (signature)
 
                                          Harold B. Smith
 
                                          --------------------------------------
                                          (printed name)
   10
 
                            ILLINOIS TOOL WORKS INC.
 
                            FORM 10-K ANNUAL REPORT
                            ------------------------
 
                               POWER OF ATTORNEY
                            ------------------------
 
     KNOW ALL MEN BY THESE PRESENTS, that the undersigned whose signature
appears below constitutes and appoints W. James Farrell, Harold B. Smith, and
Stewart S. Hudnut, and each of them, his true and lawful attorneys-in-fact and
agents, with full power of substitution and resubstitution for him and in his
name, place and stead, in any and all capacities, to sign the Company's Form
10-K Annual Report and to file the same, with all exhibits thereto, and other
documents in connection therewith, with the Securities and Exchange Commission,
granting unto said attorneys-in-fact and agents full power and authority to do
and perform each and every act and thing requisite and necessary to be done in
and about the premises, as fully to all intents and purposes as he might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitute or substitutes, may lawfully
do or cause to be done by virtue thereof.
 
     IN WITNESS WHEREOF, the undersigned has executed this power of attorney
this 20th day of February 1998.
 
                                          /s/ ORMAND J. WADE
 
                                          --------------------------------------
                                          (signature)
 
                                          Ormand J. Wade
 
                                          --------------------------------------
                                          (printed name)