Exhibit 31
Rule 13a-14(a) Certification
I, David B. Speer, certify that:
| 1. | I have reviewed this report on Form 10-Q/A of Illinois Tool Works Inc.; and |
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report. |
Dated: November 12, 2008 | /s/ David B. Speer |
| David B. Speer |
| Chairman & Chief Executive Officer |
Exhibit 31
Rule 13a-14(a) Certification
I, Ronald D. Kropp, certify that:
| 1. | I have reviewed this report on Form 10-Q/A of Illinois Tool Works Inc.; and |
| 2. | Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report. |
Dated: November 12, 2008 | /s/ Ronald D. Kropp |
| Ronald D. Kropp |
| Senior Vice President & Chief Financial Officer |
