UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 16)*

                                Fastenal Company
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                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    311900104
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                                 (CUSIP Number)

                                December 31, 2003
--------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

         [_] Rule 13d-1(b)
         [_] Rule 13d-1(c)
         [X] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

Potential persons who are to respond to the collection of information contained
in this form are not required to respond unless the form displays a currently
valid OMB control number.

                                  Page 1 of 5



CUSIP NO. 311900104                    13G
         ------------
--------------------------------------------------------------------------------
 1.   Names of Reporting Persons.
      I.R.S. Identification Nos. of Above Persons (entities only).

        Robert A. Kierlin
--------------------------------------------------------------------------------
 2.   Check the Appropriate Box If a Member of a Group*

                                                                (a) [_]
        Not Applicable                                          (b) [_]
--------------------------------------------------------------------------------
 3.   SEC Use Only

--------------------------------------------------------------------------------
 4.   Citizenship or Place of Organization

        United States
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                     5.   Sole Voting Power
   NUMBER OF
                           6,277,182
    SHARES         -------------------------------------------------------------
 BENEFICIALLY        6.   Shared Voting Power
   OWNED BY
                          200
     EACH          -------------------------------------------------------------
  REPORTING          7.   Sole Dispositive Power
    PERSON
                           6,277,182
     WITH          -------------------------------------------------------------
                     8.   Shared Dispositive Power

                           200
--------------------------------------------------------------------------------
 9.   Aggregate Amount Beneficially Owned by Each Reporting Person

        6,277,382
--------------------------------------------------------------------------------
10.   Check If the Aggregate Amount in Row (9) Excludes Certain Shares*

                                                                         [_]
       Not Applicable
--------------------------------------------------------------------------------
11.   Percent of Class Represented by Amount in Row (9)

        8.3%
--------------------------------------------------------------------------------
12.   Type of Reporting Person*

        IN
--------------------------------------------------------------------------------

                      *SEE INSTRUCTION BEFORE FILLING OUT!

                                   Page 2 of 5



Item 1.   (a)  Name of Issuer

               Fastenal Company

          (b)  Address of Issuer's Principal Executive Offices

               2001 Theurer Boulevard
               Winona, Minnesota 55987-1500

Item 2.   (a)  Name of Person Filing

               This filing is made by Robert A. Kierlin

          (b)  Address of Principal Business Office or, if none, Residence

               Robert A. Kierlin
               Fastenal Company
               2001 Theurer Boulevard
               Winona, Minnesota 55987-1500

          (c)  Citizenship

               Robert A. Kierlin is a citizen of the United States

          (d)  Title of Class of Securities

               Common Stock, $.01 par value

          (e)  CUSIP Number

               311900104

Item 3.   If this statement is filed pursuant to (S)(S) 240.13d-1(b) or
          240.13d-2(b) or (c), check whether the person filing is a:

          (a)  [_] Broker or dealer registered under Section 15 of the Act.

          (b)  [_] Bank as defined in Section 3(a)(6) of the Act.

          (c)  [_] Insurance company as defined in Section 3(a)(19) of the
                   Act.

          (d)  [_] Investment company registered under Section 8 of the
                   Investment Company Act of 1940.

          (e)  [_] An investment adviser in accordance with (S)
                   240.13d-1(b)(1)(ii)(E).

          (f)  [_] An employee benefit plan or endowment fund in accordance
                   with (S) 240.13d-1(b)(1)(ii)(F).

          (g)  [_] A parent holding company or control person in accordance
                   with (S) 240.13d-1(b)(1)(ii)(G).

          (h)  [_] A savings association as defined in Section 3(b) of the
                   Federal Deposit Insurance Act.

          (i)  [_] A church plan that is excluded from the definition of an
                   investment company under Section 3(c)(14) of the Investment
                   Company Act of 1940.

          (j)  [_] Group, in accordance with (S) 240.13d-1(b)(1)(ii)(J).

                   Not Applicable

                                   Page 3 of 5



Item 4.   Ownership

          (a)  Amount Beneficially Owned

               6,277,382

          (b)  Percent of Class

               8.3%

          (c)  Number of shares as to which such person has:

               (i)   Sole power to vote or to direct the vote

                     6,277,182

               (ii)  Shared power to vote or to direct the vote

                     200

               (iii) Sole power to dispose or to direct the disposition of

                     6,277,182

               (iv) Shared power to dispose or to direct the disposition of

                     200

     See Item 6 for further information regarding the nature of the reporting
person's beneficial ownership of certain of the above-referenced shares.

Item 5.   Ownership of Five Percent or Less of a Class

          Not Applicable

     If this statement is being filed to report the fact that as of the date
hereof the reporting person has ceased to be the beneficial owner of more than
five percent of the class of securities, check the following [_].

Item 6.   Ownership of More than Five Percent on Behalf of Another Person.

     The shares listed in Item 4 include 200 shares held by the reporting
person's wife. The reporting person disclaims beneficial ownership of such
shares. The reporting person's wife has the right to receive and the power to
direct the receipt of dividends from, and the proceeds of the sale of, the
shares held by her.

Item 7.   Identification and Classification of the Subsidiary Which Acquired the
          Security Being Reported on By the Parent Holding Company

          Not Applicable

Item 8.   Identification and Classification of Members of the Group

          Not Applicable

Item 9.   Notice of Dissolution of Group

          Not Applicable

Item 10.  Certification

          Not Applicable

                                   Page 4 of 5



SIGNATURE

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

                                               December 31, 2003
                                   ---------------------------------------------
                                                   Date

                                              /s/ Robert A. Kierlin
                                   ---------------------------------------------
                                                   Signature

                                               Robert A. Kierlin
                                   ---------------------------------------------
                                                  Name/Title

     The original statement shall be signed by each person on whose behalf the
statement is filed or his authorized representative. If the statement is signed
on behalf of a person by his authorized representative other than an executive
officer or general partner of the filing person, evidence of the
representative's authority to sign on behalf of such person shall be filed with
the statement, provided, however, that a power of attorney for this purpose
which is already on file with the Commission may be incorporated by reference.
The name and any title of each person who signs the statement shall be typed or
printed beneath his signature.

     NOTE: Schedules filed in paper format shall include a signed original and
five copies of the schedule, including all exhibits. See (S) 240.13d-7 for other
parties for whom copies are to be sent.

     Attention: Intentional misstatements or omissions of fact constitute
Federal criminal violations (See 18 U.S.C. 1001).

                                   Page 5 of 5