<PAGE>   1
     As filed with the Securities and Exchange Commission on April 13, 2000
                                                   Registration No. 333-________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                          -----------------------------

                                    FORM S-8

             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                          -----------------------------

                               GRANT PRIDECO, INC.
             (Exact name of registrant as specified in its charter)


<TABLE>
<S>                                                                                          <C>
                              DELAWARE                                                           76-0312499
           (State or other jurisdiction of incorporation                                      (I.R.S. Employer
                          or organization)                                                   Identification No.)

                 1450 LAKE ROBBINS DRIVE, SUITE 600
                        THE WOODLANDS, TEXAS                                                        77380
              (Address of Principal Executive Officer)                                           (Zip Code)
</TABLE>


    GRANT PRIDECO, INC. 2000 EMPLOYEE STOCK OPTION AND RESTRICTED STOCK PLAN
        GRANT PRIDECO, INC. 2000 NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN
            GRANT PRIDECO, INC. EXECUTIVE DEFERRED COMPENSATION PLAN
        GRANT PRIDECO, INC. FOREIGN EXECUTIVE DEFERRED COMPENSATION PLAN
    GRANT PRIDECO, INC. DEFERRED COMPENSATION PLAN FOR NON-EMPLOYEE DIRECTORS
             DISTRIBUTION AGREEMENT BETWEEN GRANT PRIDECO, INC. AND
                        WEATHERFORD INTERNATIONAL, INC.
                            (Full title of the plans)

                          -----------------------------

                                  JOHN C. COBLE
                               GRANT PRIDECO, INC.
                             1450 LAKE ROBBINS DRIVE
                           THE WOODLANDS, TEXAS 77380
                     (Name and address of agent for service)

                                  281/297-8500
          (Telephone number, including area code, of agent for service)

                                 With a copy to:
                           FULBRIGHT & JAWORSKI L.L.P.
                            1301 MCKINNEY, SUITE 5100
                            HOUSTON, TEXAS77010-3095
                                 (713) 651-5151
                          ATTENTION: CHARLES L. STRAUSS

                          -----------------------------

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
====================================================================================================================================
    TITLE OF SECURITIES                                      PROPOSED MAXIMUM              PROPOSED MAXIMUM            AMOUNT OF
     TO BE REGISTERED         AMOUNT TO BE REGISTERED   OFFERING PRICE PER SHARE(1)   AGGREGATE OFFERING PRICE(1)   REGISTRATION FEE
------------------------------------------------------------------------------------------------------------------------------------
<S>                           <C>                       <C>                           <C>                           <C>
Common Stock,
par value $.01 per share       14,030,000 shares (2)             $17.125                 $240,263,750                   $63,430
====================================================================================================================================
</TABLE>


 (1) Estimated solely for the purpose of calculating the registration fee
     pursuant to Rule 457(c) under the Securities Act of 1933 and based upon the
     average of the high and low sales prices of a share of Common Stock on a
     "when-distributed basis" as reported by the New York Stock Exchange, Inc.
     on April 10, 2000.
(2)  Consists of (a) 10,000,000 shares of Common Stock for the Grant Prideco,
     Inc. Employee Stock Option Plan, (b) 780,000 shares of Common Stock for the
     Grant Prideco, Inc. Non-Employee Director Stock Option Plan; (c) 1,500,000
     shares of Common Stock to be issued to certain holders of options to
     purchase Weatherford common stock pursuant to the terms and conditions of
     the Distribution Agreement dated April 14, 2000, between Grant Prideco,
     Inc. and Weatherford International, Inc. (the "Distribution Agreement"),
     (d) 1,000,000 shares of Common Stock to be issued to certain participants
     in Weatherford International, Inc.'s Deferred Compensation Plans pursuant
     to the terms and conditions of the Distribution Agreement; (e) 500,000
     shares to be issued pursuant to the terms and conditions of the Grant
     Prideco, Inc. Executive Deferred Compensation Plan; (f)150,000 shares to be
     issued pursuant to the terms and conditions of Grant Prideco, Inc.'s
     Foreign Deferred Compensation Plan; (g) 100,000 shares to be issued
     pursuant to the terms and conditions of Grant Prideco, Inc.'s Non-Employee
     Director Executive Deferred Compensation Plan; and (h) an indeterminable
     number of shares of Common Stock issuable as a result of the anti-dilution
     provisions of each of the foregoing plans or agreements.

<PAGE>   2
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         Grant Prideco, Inc., a Delaware corporation (the "Company" or
"Registrant") incorporates by reference in this Registration Statement the
following:

         (i) the Registrant's effective Registration Statement on Form 10 (File
No. 001-15243) (including without limitation the description of the Registrant's
Common Stock contained therein); and

         (ii) all documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934 subsequent to the
date of the filing hereof and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of filing of such documents.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Curtis W. Huff, the Vice President, Interim General Counsel and
Secretary of Grant Prideco, Inc., is of-counsel at Fulbright & Jaworski L.L.P.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Under Delaware law, a corporation may include provisions in its
certificate of incorporation that will relieve its directors of monetary
liability for breaches of their fiduciary duty to the corporation, except under
certain circumstances, including a breach of the director's duty of loyalty,
acts or omissions of the director not in good faith or which involve intentional
misconduct or a knowing violation of law, the approval of an improper payment of
a dividend or an improper purchase by the corporation of stock or any
transaction from which the director derived an improper personal benefit. The
Registrant's Restated Certificate of Incorporation provides that the
Registrant's directors are not liable to the Registrant or its stockholders for
monetary damages for breach of their fiduciary duty, subject to the described
exceptions specified by Delaware law.

         Under Section 145 of the Delaware General Corporation Law and our
bylaws, we are obligated to indemnify our present and former directors and
officers and may indemnify other employees and individuals against expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement in
connection with specified actions, suits or proceedings, whether civil,
criminal, administrative or investigative (other than an action by or in the
right of the corporation, a "derivative action"), if the person to whom
indemnity is granted acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to our best interests, and with respect to any
criminal action or proceeding, had no reasonable cause to believe his or her
conduct was unlawful. A similar standard of care is applicable in the case of
derivative actions, except that indemnification extends only to expenses
(including attorneys' fees) incurred in connection with defense or settlement of
such an action, and the Delaware General Corporation Law requires court approval
before there can be any indemnification where the person seeking indemnification
has been found liable to Grant Prideco.

         Section 145 of the Delaware General Corporation Law also empowers the
Registrant to purchase and maintain insurance on behalf of any person who is or
was an officer or director of the Registrant against liability asserted against
or incurred by him in any such capacity, whether or not the Registrant would
have the power to indemnify such officer or director against such liability
under the provisions of Section 145. The Registrant has purchased and maintains
a directors' and officers' liability policy for such purposes.


                                      II-1
<PAGE>   3
ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not applicable.

ITEM 8.  EXHIBITS.

     4.1   Form of Restated Certificate of Incorporation (incorporated by
           reference from exhibit no. 3.1 of the Registrant's Registration
           Statement on Form 10 (File No. 001-15423).
     4.2   Form of Restated Bylaws of the Registrant (incorporated by reference
           from exhibit no. 3.2 of the Registrant's Registration Statement on
           Form 10 (File No. 001-15423).
     4.3   Distribution Agreement dated April 14, 2000, between Grant Prideco,
           Inc. and Weatherford International, Inc. (incorporated by reference
           from exhibit no. 2.1 of the Registrant's Registration Statement on
           Form 10 (File No. 001-15423).
     4.4   Grant Prideco 2000 Employee Stock Option and Restricted Stock Plan
           (incorporated by reference from exhibit no. 10.5 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.5   Grant Prideco, Inc. 2000 Non-Employee Director Stock Option Plan
           (incorporated by reference from exhibit no. 10.6 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.6   Grant Prideco, Inc. Executive Deferred Compensation Plan
           (incorporated by reference from exhibit No. 10.9 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423)
     4.7   Grant Prideco, Inc. Foreign Executive Deferred Compensation Plan
           (incorporated by reference from exhibit no. 10.8 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.8   Grant Prideco, Inc. Deferred Compensation Plan for Non-Employee
           Directors (incorporated by reference from exhibit no. 10.10 of the
           Registrant's Registration Statement on Form 10 (File No. 001-15423).
     4.9   Form of Subordinated Promissory Note payable to Weatherford
           International, Inc. (incorporated by reference from exhibit no. 4.1
           of the Registrant's Registration Statement on Form 10
           (File No. 001-15423).
     5.1   Opinion of Fulbright & Jaworski
    23.1   Consent of Fulbright & Jaworski (included in Exhibit 5.1)
    99.1   Consent of Elliott M. Fried
    99.2   Consent of Sheldon B. Lubar
    99.3   Consent of William E. Macaulay
    99.4   Consent of Robert K. Moses
    99.5   Consent of Robert A. Rayne

ITEM 9.  UNDERTAKINGS.

         The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement:

         (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

         (ii) To reflect in the prospectus any facts or events arising after the
effective date of this Registration Statement (or the most recent post-effective
amendment hereof) which, individually or in the aggregate, represent a
fundamental change in the information set forth in this Registration Statement.
Notwithstanding the foregoing, any increase or decrease in volume of securities
offered (if the total dollar volume of securities offered would not exceed that
which was registered) and any deviation from the low or high end of the
estimated maximum offering range may be reflected in the form of prospectus
filed with the Securities and Exchange Commission pursuant to Rule 424(b) if, in
the aggregate, the changes in volume and price represent no more than a 20%
change in the maximum aggregate offering price set forth in the "Calculation of
Registration Fee" table in the effective registration statement; and

         (iii) To include any material information with respect to the plan of
distribution not previously disclosed in this Registration Statement or any
material change to such information in this Registration Statement;

         Provided, however, that paragraphs (1)(i) and (1)(ii) do not apply if
the information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the
Securities


                                      II-2
<PAGE>   4
and Exchange Commission by the Registrant pursuant to Section 13 or Section
15(d) of the Securities Exchange Act of 1934 that are incorporated by reference
in this Registration Statement.

         (2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

         (4) That, for purposes of determining any liability under the
Securities Act of 1933, each filing of the Registrant's annual report pursuant
to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act of 1933 and is, therefore, unenforceable. In the event that a
claim for indemnification against such liabilities (other than the payment by
the Registrant of expenses incurred or paid by a director, officer or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.


                                      II-3
<PAGE>   5
                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Houston, State of Texas, on April 13, 2000.


                                            GRANT PRIDECO, INC.


                                            By: /s/ JOHN C. COBLE
                                            ---------------------------------
                                            John C. Coble
                                            Chief Executive Officer,
                                            President and Director
                                            (Principal Executive Officer)


                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints John C. Coble and Frances R. Powell, or
any of them, his true and lawful attorney-in-fact and agent, with full power of
substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments (including post-effective
amendments) to this Registration Statement, and to file the same and all
exhibits thereto, and all documents in connection therewith, with the Securities
and Exchange Commission, granting said attorney-in-fact and agent, and any of
them, 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 attorney-in-fact and agent, or any of them, or his or
their substitute or substitutes, may lawfully do or cause to be done by virtue
hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.

<TABLE>
<CAPTION>
NAME                                      TITLE                                   DATE
----                                      -----                                   ----
<S>                                       <C>                                     <C>
/s/ BERNARD J. DUROC-DANNER               Chairman of the Board and Director      April 13, 2000
----------------------------------------
Bernard J. Duroc-Danner

/s/ JOHN C. COBLE                         President                               April 13, 2000
----------------------------------------  (principal executive officer)
John C. Coble

/s/ FRANCES R. POWELL                     Vice President and Chief Financial      April 13, 2000
----------------------------------------  Officer (principal financial and
Frances R. Powell                         accounting officer)

/s/ CURTIS W. HUFF                        Vice President, Interim General         April 13, 2000
----------------------------------------  Counsel, Secretary and Director
Curtis W. Huff
</TABLE>


                                      II-4
<PAGE>   6
                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
EXHIBIT
NUMBER    DESCRIPTION
-------   -----------
<S>       <C>
  4.1     Form of Restated Certificate of Incorporation (incorporated by
          reference from exhibit no. 3.1 of the Registrant's Registration
          Statement on Form 10 (File No. 001-15423).
  4.2     Form of Restated Bylaws of the Registrant (incorporated by reference
          from exhibit no. 3.2 of the Registrant's Registration Statement on
          Form 10 (File No. 001-15423).
  4.3     Distribution Agreement dated April 14, 2000, between Grant Prideco,
          Inc. and Weatherford International, Inc. (incorporated by reference
          from exhibit no. 2.1 of the Registrant's Registration Statement on
          Form 10 (File No. 001-15423).
  4.4     Grant Prideco 2000 Employee Stock Option and Restricted Stock Plan
          (incorporated by reference from exhibit no. 10.5 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.5     Grant Prideco, Inc. 2000 Non-Employee Director Stock Option Plan
          (incorporated by reference from exhibit no. 10.6 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.6     Grant Prideco, Inc. Executive Deferred Compensation Plan (incorporated
          by reference from exhibit No. 10.9 of the Registrant's Registration
          Statement on Form 10 (File No. 001-15423)
  4.7     Grant Prideco, Inc. Foreign Executive Deferred Compensation Plan
          (incorporated by reference from exhibit no. 10.8 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.8     Grant Prideco, Inc. Deferred Compensation Plan for Non-Employee
          Directors (incorporated by reference from exhibit no. 10.10 of the
          Registrant's Registration Statement on Form 10 (File No. 001-15423).
  4.9     Form of Subordinated Promissory Note payable to Weatherford
          International, Inc. (incorporated by reference from exhibit no. 4.1 of
          the Registrant's Registration Statement on Form 10 (File No.
          001-15423).
  5.1     Opinion of Fulbright & Jaworski
 23.1     Consent of Fulbright & Jaworski (included in Exhibit 5.1)
 99.1     Consent of Elliott M. Fried
 99.2     Consent of Sheldon B. Lubar
 99.3     Consent of William E. Macaulay
 99.4     Consent of Robert K. Moses
 99.5     Consent of Robert A. Rayne
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "GRANT PRIDECO, INC.", "secsgml_size_bytes": 21919}]
{"company-data": {"conformed-name": "GRANT PRIDECO INC", "cik": "0001097313", "assigned-sic": "3533", "irs-number": "760312499", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-34746", "film-number": "600791"}, "business-address": {"street1": "1450 LAKE ROBBINS DRIVE", "street2": "SUITE 600", "city": "THE WOODLANDS", "state": "TX", "zip": "77380", "phone": "2812978500"}, "mail-address": {"street1": "1450 LAKE ROBBINS DRIVE", "street2": "SUITE 600", "city": "THE WOODLANDS", "state": "TX", "zip": "77380"}}
1
     As filed with the Securities and Exchange Commission on April 13, 2000
                                                   Registration No. 333-________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                          -----------------------------

                                    FORM S-8

             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                          -----------------------------

                               GRANT PRIDECO, INC.
             (Exact name of registrant as specified in its charter)
DELAWARE                                                           76-0312499
           (State or other jurisdiction of incorporation                                      (I.R.S. Employer
                          or organization)                                                   Identification No.)

                 1450 LAKE ROBBINS DRIVE, SUITE 600
                        THE WOODLANDS, TEXAS                                                        77380
              (Address of Principal Executive Officer)                                           (Zip Code)
GRANT PRIDECO, INC. 2000 EMPLOYEE STOCK OPTION AND RESTRICTED STOCK PLAN
        GRANT PRIDECO, INC. 2000 NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN
            GRANT PRIDECO, INC. EXECUTIVE DEFERRED COMPENSATION PLAN
        GRANT PRIDECO, INC. FOREIGN EXECUTIVE DEFERRED COMPENSATION PLAN
    GRANT PRIDECO, INC. DEFERRED COMPENSATION PLAN FOR NON-EMPLOYEE DIRECTORS
             DISTRIBUTION AGREEMENT BETWEEN GRANT PRIDECO, INC. AND
                        WEATHERFORD INTERNATIONAL, INC.
                            (Full title of the plans)

                          -----------------------------

                                  JOHN C. COBLE
                               GRANT PRIDECO, INC.
                             1450 LAKE ROBBINS DRIVE
                           THE WOODLANDS, TEXAS 77380
                     (Name and address of agent for service)

                                  281/297-8500
          (Telephone number, including area code, of agent for service)

                                 With a copy to:
                           FULBRIGHT & JAWORSKI L.L.P.
                            1301 MCKINNEY, SUITE 5100
                            HOUSTON, TEXAS77010-3095
                                 (713) 651-5151
                          ATTENTION: CHARLES L. STRAUSS

                          -----------------------------

                         CALCULATION OF REGISTRATION FEE
====================================================================================================================================
    TITLE OF SECURITIES                                      PROPOSED MAXIMUM              PROPOSED MAXIMUM            AMOUNT OF
     TO BE REGISTERED         AMOUNT TO BE REGISTERED   OFFERING PRICE PER SHARE(1)   AGGREGATE OFFERING PRICE(1)   REGISTRATION FEE
------------------------------------------------------------------------------------------------------------------------------------
Common Stock,
par value $.01 per share       14,030,000 shares (2)             $17.125                 $240,263,750                   $63,430
====================================================================================================================================
(1) Estimated solely for the purpose of calculating the registration fee
     pursuant to Rule 457(c) under the Securities Act of 1933 and based upon the
     average of the high and low sales prices of a share of Common Stock on a
     "when-distributed basis" as reported by the New York Stock Exchange, Inc.
     on April 10, 2000.
(2)  Consists of (a) 10,000,000 shares of Common Stock for the Grant Prideco,
     Inc. Employee Stock Option Plan, (b) 780,000 shares of Common Stock for the
     Grant Prideco, Inc. Non-Employee Director Stock Option Plan; (c) 1,500,000
     shares of Common Stock to be issued to certain holders of options to
     purchase Weatherford common stock pursuant to the terms and conditions of
     the Distribution Agreement dated April 14, 2000, between Grant Prideco,
     Inc. and Weatherford International, Inc. (the "Distribution Agreement"),
     (d) 1,000,000 shares of Common Stock to be issued to certain participants
     in Weatherford International, Inc.'s Deferred Compensation Plans pursuant
     to the terms and conditions of the Distribution Agreement; (e) 500,000
     shares to be issued pursuant to the terms and conditions of the Grant
     Prideco, Inc. Executive Deferred Compensation Plan; (f)150,000 shares to be
     issued pursuant to the terms and conditions of Grant Prideco, Inc.'s
     Foreign Deferred Compensation Plan; (g) 100,000 shares to be issued
     pursuant to the terms and conditions of Grant Prideco, Inc.'s Non-Employee
     Director Executive Deferred Compensation Plan; and (h) an indeterminable
     number of shares of Common Stock issuable as a result of the anti-dilution
     provisions of each of the foregoing plans or agreements.
2
                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         Grant Prideco, Inc., a Delaware corporation (the "Company" or
"Registrant") incorporates by reference in this Registration Statement the
following:

         (i) the Registrant's effective Registration Statement on Form 10 (File
No. 001-15243) (including without limitation the description of the Registrant's
Common Stock contained therein); and

         (ii) all documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934 subsequent to the
date of the filing hereof and prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of filing of such documents.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not applicable.

ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.

         Curtis W. Huff, the Vice President, Interim General Counsel and
Secretary of Grant Prideco, Inc., is of-counsel at Fulbright & Jaworski L.L.P.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         Under Delaware law, a corporation may include provisions in its
certificate of incorporation that will relieve its directors of monetary
liability for breaches of their fiduciary duty to the corporation, except under
certain circumstances, including a breach of the director's duty of loyalty,
acts or omissions of the director not in good faith or which involve intentional
misconduct or a knowing violation of law, the approval of an improper payment of
a dividend or an improper purchase by the corporation of stock or any
transaction from which the director derived an improper personal benefit. The
Registrant's Restated Certificate of Incorporation provides that the
Registrant's directors are not liable to the Registrant or its stockholders for
monetary damages for breach of their fiduciary duty, subject to the described
exceptions specified by Delaware law.

         Under Section 145 of the Delaware General Corporation Law and our
bylaws, we are obligated to indemnify our present and former directors and
officers and may indemnify other employees and individuals against expenses
(including attorneys' fees), judgments, fines and amounts paid in settlement in
connection with specified actions, suits or proceedings, whether civil,
criminal, administrative or investigative (other than an action by or in the
right of the corporation, a "derivative action"), if the person to whom
indemnity is granted acted in good faith and in a manner he or she reasonably
believed to be in or not opposed to our best interests, and with respect to any
criminal action or proceeding, had no reasonable cause to believe his or her
conduct was unlawful. A similar standard of care is applicable in the case of
derivative actions, except that indemnification extends only to expenses
(including attorneys' fees) incurred in connection with defense or settlement of
such an action, and the Delaware General Corporation Law requires court approval
before there can be any indemnification where the person seeking indemnification
has been found liable to Grant Prideco.

         Section 145 of the Delaware General Corporation Law also empowers the
Registrant to purchase and maintain insurance on behalf of any person who is or
was an officer or director of the Registrant against liability asserted against
or incurred by him in any such capacity, whether or not the Registrant would
have the power to indemnify such officer or director against such liability
under the provisions of Section 145. The Registrant has purchased and maintains
a directors' and officers' liability policy for such purposes.

                                      II-1
3
ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not applicable.

ITEM 8.  EXHIBITS.

     4.1   Form of Restated Certificate of Incorporation (incorporated by
           reference from exhibit no. 3.1 of the Registrant's Registration
           Statement on Form 10 (File No. 001-15423).
     4.2   Form of Restated Bylaws of the Registrant (incorporated by reference
           from exhibit no. 3.2 of the Registrant's Registration Statement on
           Form 10 (File No. 001-15423).
     4.3   Distribution Agreement dated April 14, 2000, between Grant Prideco,
           Inc. and Weatherford International, Inc. (incorporated by reference
           from exhibit no. 2.1 of the Registrant's Registration Statement on
           Form 10 (File No. 001-15423).
     4.4   Grant Prideco 2000 Employee Stock Option and Restricted Stock Plan
           (incorporated by reference from exhibit no. 10.5 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.5   Grant Prideco, Inc. 2000 Non-Employee Director Stock Option Plan
           (incorporated by reference from exhibit no. 10.6 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.6   Grant Prideco, Inc. Executive Deferred Compensation Plan
           (incorporated by reference from exhibit No. 10.9 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423)
     4.7   Grant Prideco, Inc. Foreign Executive Deferred Compensation Plan
           (incorporated by reference from exhibit no. 10.8 of the Registrant's
           Registration Statement on Form 10 (File No. 001-15423).
     4.8   Grant Prideco, Inc. Deferred Compensation Plan for Non-Employee
           Directors (incorporated by reference from exhibit no. 10.10 of the
           Registrant's Registration Statement on Form 10 (File No. 001-15423).
     4.9   Form of Subordinated Promissory Note payable to Weatherford
           International, Inc. (incorporated by reference from exhibit no. 4.1
           of the Registrant's Registration Statement on Form 10
           (File No. 001-15423).
     5.1   Opinion of Fulbright & Jaworski
    23.1   Consent of Fulbright & Jaworski (included in Exhibit 5.1)
    99.1   Consent of Elliott M. Fried
    99.2   Consent of Sheldon B. Lubar
    99.3   Consent of William E. Macaulay
    99.4   Consent of Robert K. Moses
    99.5   Consent of Robert A. Rayne

ITEM 9.  UNDERTAKINGS.

         The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this Registration Statement:

         (i) To include any prospectus required by Section 10(a)(3) of the
Securities Act of 1933;

         (ii) To reflect in the prospectus any facts or events arising after the
effective date of this Registration Statement (or the most recent post-effective
amendment hereof) which, individually or in the aggregate, represent a
fundamental change in the information set forth in this Registration Statement.
Notwithstanding the foregoing, any increase or decrease in volume of securities
offered (if the total dollar volume of securities offered would not exceed that
which was registered) and any deviation from the low or high end of the
estimated maximum offering range may be reflected in the form of prospectus
filed with the Securities and Exchange Commission pursuant to Rule 424(b) if, in
the aggregate, the changes in volume and price represent no more than a 20%
change in the maximum aggregate offering price set forth in the "Calculation of
Registration Fee" table in the effective registration statement; and

         (iii) To include any material information with respect to the plan of
distribution not previously disclosed in this Registration Statement or any
material change to such information in this Registration Statement;

         Provided, however, that paragraphs (1)(i) and (1)(ii) do not apply if
the information required to be included in a post-effective amendment by those
paragraphs is contained in periodic reports filed with or furnished to the
Securities

                                      II-2
4
and Exchange Commission by the Registrant pursuant to Section 13 or Section
15(d) of the Securities Exchange Act of 1934 that are incorporated by reference
in this Registration Statement.

         (2) That, for the purpose of determining any liability under the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered which remain unsold at the termination of
the offering.

         (4) That, for purposes of determining any liability under the
Securities Act of 1933, each filing of the Registrant's annual report pursuant
to Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is
incorporated by reference in this Registration Statement shall be deemed to be a
new registration statement relating to the securities offered herein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

         Insofar as indemnification for liabilities arising under the Securities
Act of 1933 may be permitted to directors, officers and controlling persons of
the Registrant pursuant to the foregoing provisions, or otherwise, the
Registrant has been advised that in the opinion of the Securities and Exchange
Commission such indemnification is against public policy as expressed in the
Securities Act of 1933 and is, therefore, unenforceable. In the event that a
claim for indemnification against such liabilities (other than the payment by
the Registrant of expenses incurred or paid by a director, officer or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.

                                      II-3
5
                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Houston, State of Texas, on April 13, 2000.

                                            GRANT PRIDECO, INC.

                                            By: /s/ JOHN C. COBLE
                                            ---------------------------------
                                            John C. Coble
                                            Chief Executive Officer,
                                            President and Director
                                            (Principal Executive Officer)

                                POWER OF ATTORNEY

         KNOW ALL MEN BY THESE PRESENTS, that each individual whose signature
appears below constitutes and appoints John C. Coble and Frances R. Powell, or
any of them, his true and lawful attorney-in-fact and agent, with full power of
substitution and resubstitution, for him and in his name, place and stead, in
any and all capacities, to sign any and all amendments (including post-effective
amendments) to this Registration Statement, and to file the same and all
exhibits thereto, and all documents in connection therewith, with the Securities
and Exchange Commission, granting said attorney-in-fact and agent, and any of
them, 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 attorney-in-fact and agent, or any of them, or his or
their substitute or substitutes, may lawfully do or cause to be done by virtue
hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated.
NAME                                      TITLE                                   DATE
----                                      -----                                   ----
/s/ BERNARD J. DUROC-DANNER               Chairman of the Board and Director      April 13, 2000
----------------------------------------
Bernard J. Duroc-Danner

/s/ JOHN C. COBLE                         President                               April 13, 2000
----------------------------------------  (principal executive officer)
John C. Coble

/s/ FRANCES R. POWELL                     Vice President and Chief Financial      April 13, 2000
----------------------------------------  Officer (principal financial and
Frances R. Powell                         accounting officer)

/s/ CURTIS W. HUFF                        Vice President, Interim General         April 13, 2000
----------------------------------------  Counsel, Secretary and Director
Curtis W. Huff
II-4
6
                                  EXHIBIT INDEX
EXHIBIT
NUMBER    DESCRIPTION
-------   -----------
4.1     Form of Restated Certificate of Incorporation (incorporated by
          reference from exhibit no. 3.1 of the Registrant's Registration
          Statement on Form 10 (File No. 001-15423).
  4.2     Form of Restated Bylaws of the Registrant (incorporated by reference
          from exhibit no. 3.2 of the Registrant's Registration Statement on
          Form 10 (File No. 001-15423).
  4.3     Distribution Agreement dated April 14, 2000, between Grant Prideco,
          Inc. and Weatherford International, Inc. (incorporated by reference
          from exhibit no. 2.1 of the Registrant's Registration Statement on
          Form 10 (File No. 001-15423).
  4.4     Grant Prideco 2000 Employee Stock Option and Restricted Stock Plan
          (incorporated by reference from exhibit no. 10.5 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.5     Grant Prideco, Inc. 2000 Non-Employee Director Stock Option Plan
          (incorporated by reference from exhibit no. 10.6 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.6     Grant Prideco, Inc. Executive Deferred Compensation Plan (incorporated
          by reference from exhibit No. 10.9 of the Registrant's Registration
          Statement on Form 10 (File No. 001-15423)
  4.7     Grant Prideco, Inc. Foreign Executive Deferred Compensation Plan
          (incorporated by reference from exhibit no. 10.8 of the Registrant's
          Registration Statement on Form 10 (File No. 001-15423).
  4.8     Grant Prideco, Inc. Deferred Compensation Plan for Non-Employee
          Directors (incorporated by reference from exhibit no. 10.10 of the
          Registrant's Registration Statement on Form 10 (File No. 001-15423).
  4.9     Form of Subordinated Promissory Note payable to Weatherford
          International, Inc. (incorporated by reference from exhibit no. 4.1 of
          the Registrant's Registration Statement on Form 10 (File No.
          001-15423).
  5.1     Opinion of Fulbright & Jaworski
 23.1     Consent of Fulbright & Jaworski (included in Exhibit 5.1)
 99.1     Consent of Elliott M. Fried
 99.2     Consent of Sheldon B. Lubar
 99.3     Consent of William E. Macaulay
 99.4     Consent of Robert K. Moses
 99.5     Consent of Robert A. Rayne