<PAGE>
                                                                   EXHIBIT 10.10

November 9, 2000



Mr. Marshall Danby
318 Bayshore Drive
Montgomery, Texas 77356

Dear Marshall:

We are pleased to offer you the position of Vice President and General Manager
of the Drill Tube International division of Grant Prideco L. P., effective on or
about December 1, 2000 (the "Start Date") with the following terms and
conditions.

POSITION

1.       Title, Grade and Reporting
         Your title will be Vice President and General Manager Drill Tube
         International, (Grant Prideco Salary Grade 23) and you will report to
         John Coble, President Grant Prideco, L. P. ("Grant Prideco"). As you
         are aware, you also will be working very closely with Steve Turner, the
         current President of our Drill Tube division. Working with Steve to
         achieve a smooth transition is very important.

2.       Job Duties
         Your job duties will be outlined by John Coble.

COMPENSATION AND BENEFITS

1.       Base Salary and Auto Allowance

         Your salary will be paid at the bi-weekly rate of $5,769.23, ("Base
         Salary"). Your next scheduled salary review will be January 1, 2002. In
         addition, you will also be eligible for an auto allowance of $600 per
         month, plus reimbursement of business mileage according to Company
         policy.

2.       Hiring Bonus

         You will be eligible for a hiring bonus of $25,000 to be paid within
         thirty (30) days of your start date at Grant Prideco.


<PAGE>


3.       Severance Agreement

         If your employment is terminated for any reason other than "for cause"
         during the first twenty-four (24) months of your start date, you will
         be eligible for a severance payment equal to one (1) year of your then
         current base pay. Your Severance Agreement will automatically expire at
         the end of the twenty-four (24) months from the Start Date. For the
         purpose of this paragraph, term " for cause" includes, but is not
         limited to, any one or more of the following occurrences: (a) your
         breach of any of any representations contained herein; (b) your
         conviction by, or enter of a plea of guilty or nolo contrendre for any
         crime (excluding traffic violations and similar misdemeanors) involving
         moral turpitude or which is punishable by imprisonment; (c) your
         commission of an act of fraud, whether prior or subsequent to the date
         hereof, upon Grant Prideco or any of its customers or affiliates; (d)
         your failure or refusal to perform his duties as required hereunder by
         this Agreement, (e) Gross negligence in performance of your duties,
         theft of the Grant Prideco's property, material violation of any duty
         of loyalty to Grant Prideco or any other material misconduct; or (f)
         Material violation of Grant Prideco's Employee Policy in effect at that
         time, including without limitation, the receipt or payment of any
         kick-back or side payment from or to any customer, supplier or vendor,
         or government.

4.       Management Incentive Program

         In addition to your base salary, you will be eligible for the
         discretionary Management Incentive Program, which will be outlined by
         John Coble. This program is designed to pay a cash incentive based on
         the attainment of pre-determined performance objectives. Management
         reserves the right to change the provisions of this program at any
         time, however, at present, your position would be eligible for a bonus
         payment of 40%/ 80%/120% (minimum/target/maximum) of your base salary
         if the objectives are achieved.

5.       Executive Deferred Compensation Plan (EDC)

         You will be eligible to participate in Grant Prideco's EDC program that
         will provide you with opportunities to both purchase and receive,
         through grants, Grant Prideco stock based upon a percentage
         contribution of your eligible cash compensation. At a minimum, Grant
         Prideco will contribute on your behalf 7 1/2% of your eligible total
         annual compensation to the plan. At your option, you may contribute up
         to 7 1/2% of your compensation and Grant Prideco will match up to 7
         1/2% on a dollar for dollar basis. The maximum amount deferred is 22
         1/2%. Vesting will take place at 20% per year over a five-year period.
         Grant Prideco stock will be acquired at then prevailing current market
         prices. A synopsis of the plan is enclosed for your review.


<PAGE>


6.       Stock Option

         You will be offered 100,000 options for Grant Prideco stock with
         three-year cliff vesting (vesting on the third anniversary of your date
         of employment) with an option price at the prevailing market rate.

7.       Benefits

         You will be eligible to participate in the Grant Prideco's medical,
         dental, vision, life and disability plans on the first day of the month
         after you complete thirty (30) days of active employment. You will also
         be eligible to participate in Grant Prideco's 401(k) plan after six (6)
         months of active employment.

8.       Vacation/Holidays

         You will be entitled to ten (10) Grant Prideco designated holidays and
         your vacation benefits will accrue at the rate of three (3) weeks
         vacation per year.

EMPLOYEE REPRESENTATIONS

1.       No Conflicts In accepting these terms of employment you represent and
         warrant that you are under no contractual or other obligation, which
         would, in any way, limit, restrict or prevent your ability to perform
         your duties hereunder.

2.       No Confidential Information You acknowledge that Grant Prideco has
         informed you that, in connection with the performance of your duties
         for Grant Prideco, you shall in no way use, disclose, or rely upon any
         trade secret or other confidential information you may possess (if any)
         by virtue of his experience in the industry (including, but not limited
         to, trade secret or confidential information of your previous
         employer).

MISCELLANEOUS

1.       Identity and Employment Eligibility

         Within three (3) business days of employment, you will need to provide
         a document or documents that establish identity and employment
         eligibility. This offer is contingent on certification of these
         documents.

2.       Drug Screening/Physical Examination

         Prior to commencement of employment, and as a condition of employment
         with Grant Prideco, you will be required to obtain a complete physical
         examination and submit a urine specimen for drug screening. Your
         employment with Grant Prideco, is contingent upon a negative drug
         screen result. Upon your acceptance of this offer, you will be provided
         with complete details for specimen collection and completion of
         physical. Upon acceptance, please contact Alicia Roye at (713) 466-8160
         to schedule a convenient time and location for this examination.


<PAGE>


3.       Patent and Confidential Information Agreement

         In accordance with Grant Prideco's Policy on Conflicts of Interest and
         Confidential Information, you will be required to sign an Agreement
         addressing these issues. A copy of this agreement is attached for your
         review.

4.       Non-Compete

         During the initial two year period of your employment following your
         start date, you agree that you will not compete against Grant Prideco
         in any capacity anywhere in North America (unless your employment is
         terminated by Grant Prideco without `cause').


This offer will remain in effect for two weeks after the date of the letter
unless the date is extended by mutual agreement. If you have any questions
regarding these items, please contact me at your earliest convenience.

Please indicate your acceptance of this agreement by signing and returning one
copy to the Human Resources Department.



     /s/ MARSHALL DENBY
------------------------------------        -----------------
Acceptance Signature                        Date


Sincerely,


/s/ WARREN AVERY
Warren Avery
Vice President Human Resources

cc:      John Coble, President