Schedule 13G/A Page _____ of _____ Pages 1 11 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. ___)* 20 NUCOR CORPORATION ___________________________________________________ (Name of Issuer) COMMON SHARES ___________________________________________________ (Title of Class of Securities) 670346105 ___________________________________________________ (Cusip Number) 12/31/2005 ___________________________________________________ (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: [X] Rule 13d-1(b) [ ] Rule 13d-1(c) [ ] 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). Schedule 13G Page _____ of _____ Pages 2 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Mutual Automobile Insurance Company 37-0533100 ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Illinois ______________________________________________________________________________ Number of 5. Sole Voting Power: 10,818,400 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 0 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 10,818,400 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 43,512 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 10,861,912 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 6.97 % ______________________________________________________________________________ 12. Type of Reporting Person: IC ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 3 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Life Insurance Company 37-0533090 ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Illinois ______________________________________________________________________________ Number of 5. Sole Voting Power: 266,200 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 0 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 266,200 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 4,040 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 270,240 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 0.17 % ______________________________________________________________________________ 12. Type of Reporting Person: IC ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 4 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Fire and Casualty Company 37-0533080 ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Illinois ______________________________________________________________________________ Number of 5. Sole Voting Power: 1,400,000 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 0 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 1,400,000 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 5,330 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 1,405,330 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 0.90 % ______________________________________________________________________________ 12. Type of Reporting Person: IC ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 5 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Investment Management Corp. ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Delaware ______________________________________________________________________________ Number of 5. Sole Voting Power: 484,000 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 7,115 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 484,000 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 7,115 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 491,115 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 0.31 % ______________________________________________________________________________ 12. Type of Reporting Person: IA ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 6 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Insurance Companies Employee Retirement Trust 36-6042145 ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Illinois ______________________________________________________________________________ Number of 5. Sole Voting Power: 933,600 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 0 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 933,600 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 4,580 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 938,180 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 0.60 % ______________________________________________________________________________ 12. Type of Reporting Person: EP ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 7 11 CUSIP No. ___670346105 ___ ___________________________________________________ 1. Name of Reporting Person and I.R.S. Identification No.: State Farm Insurance Companies Savings and Thrift Plan for U.S. Employees 37-6091823 ______________________________________________________________________________ 2. Check the appropriate box if a Member of a Group (a) _____ (b) __X__ ______________________________________________________________________________ 3. SEC USE ONLY: ______________________________________________________________________________ 4. Citizenship or Place of Organization: Illinois ______________________________________________________________________________ Number of 5. Sole Voting Power: 1,088,400 Shares _______________________________________________________________ Beneficially 6. Shared Voting Power: 0 Owned by _______________________________________________________________ Each 7. Sole Dispositive Power: 1,088,400 Reporting _______________________________________________________________ Person With 8. Shared Dispositive Power: 0 ______________________________________________________________________________ 9. Aggregate Amount Beneficially Owned by each Reporting Person: 1,088,400 ______________________________________________________________________________ 10. Check Box if the Aggregate Amount in Row 9 excludes Certain Shares: ____ ______________________________________________________________________________ 11. Percent of Class Represented by Amount in Row 9: 0.69 % ______________________________________________________________________________ 12. Type of Reporting Person: EP ______________________________________________________________________________ Schedule 13G Page _____ of _____ Pages 8 11 Item 1(a) and (b). Name and Address of Issuer & Principal Executive Offices: _________________________________________________________ NUCOR CORPORATION 2100 REXFORD ROAD CHARLOTTE, NC 28211 Item 2(a). Name of Person Filing: State Farm Mutual Automobile Insurance _____________________ Company and related entities; See Item 8 and Exhibit A Item 2(b). Address of Principal Business Office: One State Farm Plaza ____________________________________ Bloomington, IL 61710 Item 2(c). Citizenship: United States ___________ Item 2(d) and (e). Title of Class of Securities and Cusip Number: See above. _____________________________________________ Item 3. This Schedule is being filed, in accordance with 240.13d-1(b). _____________________________________________________________ See Exhibit A attached. Item 4(a). Amount Beneficially Owned: 15,055,177 shares _________________________ Item 4(b). Percent of Class: 9.67 percent pursuant to Rule 13d-3(d)(1). ________________ Item 4(c). Number of shares as to which such person has: ____________________________________________ (i) Sole Power to vote or to direct the vote: 14,990,600 (ii) Shared power to vote or to direct the vote: 7,115 (iii) Sole Power to dispose or to direct disposition of:14,990,600 (iv) Shared Power to dispose or to direct disposition of: 64,577 Item 5. Ownership of Five Percent or less of a Class: Not Applicable. ____________________________________________ Item 6. Ownership of More than Five Percent on Behalf of Another Person: N/A _______________________________________________________________ Item 7. Identification and Classification of the Subsidiary Which Acquired __________________________________________________________________ the Security being Reported on by the Parent Holding Company: N/A ______________________________________________________________ Item 8. Identification and Classification of Members of the Group: _________________________________________________________ See Exhibit A attached. Item 9. Notice of Dissolution of Group: N/A ______________________________ Schedule 13G Page _____ of _____ Pages 9 11 Item 10. Certification. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. 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. 1/24/2006 ________________________ Date /s/ Paul N. Eckley ________________________ Paul N. Eckley Senior Vice President - Investments State Farm Mutual Automobile Insurance Company State Farm Life Insurance Company State Farm Fire and Casualty Company /s/ Paul N. Eckley _________________________ Paul N. Eckley Senior Vice President State Farm Investment Management Corp. State Farm Associates` Funds Trust State Farm Variable Product Trust State Farm Mutual Fund Trust /s/ Michael L. Tipsord _________________________ Michael L. Tipsord Trustee State Farm Insurance Companies Employee Retirement Trust State Farm Insurance Companies Savings and Thrift Plan for U.S. Employees Schedule 13G Page _____ of _____ Pages 10 11 EXHIBIT A This Exhibit lists the entities affiliated with State Farm Mutual Automobile Insurance Company ("Auto Company") which might be deemed to constitute a "group" with regard to the ownership of shares reported herein. Auto Company, an Illinois-domiciled insurance company, is the parent company of multiple wholly owned insurance company subsidiaries, including State Farm Life Insurance Company, and State Farm Fire and Casualty Company. Auto Company is also the parent company of State Farm Investment Management Corp. ("SFIMC"), which is a registered transfer agent under the Securities Exchange Act of 1934 and a registered investment advisor under the Investment Advisers Act of 1940. SFIMC serves as transfer agent and investment adviser to State Farm Associates' Funds Trust, State Farm Variable Product Trust, and State Farm Mutual Fund Trust, three Delaware Business Trusts that are registered investment companies under the Investment Company Act of 1940. Auto Company also sponsors two qualified retirement plans for the benefit of its employees, which plans are named the State Farm Insurance Companies Employee Retirement Trust and the State Farm Insurance Companies Savings and Thrift Plan for U.S. Employees (collectively the "Qualified Plans"). As part of its corporate structure, Auto Company has established an Investment Department. The Investment Department is directly or indirectly responsible for managing or overseeing the management of the investment and reinvestment of assets owned by each person that has joined in filing this Schedule 13G. Moreover, the Investment Department is responsible for voting proxies or overseeing the voting of proxies related to issuers the shares of which are held by one or more entities that have joined in filing this report. Each insurance company included in this report and SFIMC have established an Investment Committee that oversees the activities of the Investment Department in managing the firm's assets. The Trustees of the Qualified Plans perform a similar role in overseeing the investment of each plan's assets. Pursuant to Rule 13d-4 each person listed in the table below expressly disclaims "beneficial ownership" as to all shares as to which such person has no right to receive the proceeds of sale of the security and disclaims that it is part of a "group". Schedule 13G Page _____ of _____ Pages 11 11 Number of Shares based Classification on Proceeds Name Under Item 3 of Sale ____ ______________ ____________ State Farm Mutual Automobile Insurance Company IC 10,861,912 shares State Farm Life Insurance Company IC 270,240 shares State Farm Fire and Casualty Company IC 1,405,330 shares State Farm Investment Management Corp. IA 0 shares State Farm Associates Funds Trust - State Farm Growth Fund IV 265,600 shares State Farm Associates Funds Trust - State Farm Balanced Fund IV 218,400 shares State Farm Variable Product Trust IV 7,115 shares State Farm Insurance Companies Employee Retirement Trust EP 938,180 shares State Farm Insurance Companies Savings and Thrift Plan for U.S. Employees EP Equities Account 872,200 shares Balanced Account 216,200 shares State Farm Mutual Fund Trust IV 0 shares ----------------- 15,055,177 shares