1 Exhibit 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to the incorporation by reference in the Registration Statement Form S-8 (No. 333-15859) pertaining to the 1996 Stock Award and Long Term Incentive Plan, the National-Oilwell, Inc. Value Appreciation and Incentive Plan A and the National-Oilwell, Inc. Value Appreciation and Incentive Plan B of our report dated July 25, 1997, with respect to the consolidated financial statements of National-Oilwell, Inc. and its predecessor, as amended, included in this Form 10-K/A. ERNST & YOUNG LLP Houston, Texas August 15, 1997