UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 21)¹

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box.  ¨

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

The information required on 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).

(Continued on following pages)

The Schedule 13D originally filed on March 29, 1990, as amended and restated in its entirely pursuant to Regulation S-T Rule 101(a)(2) on March 20, 1992, as amended by Amendment No. 1 filed on March 28, 1995, as amended by Amendment No. 2 filed on March 21, 1996, as amended by Amendment No. 3 filed on November 26, 1996, as amended by Amendment No. 4 filed on January 10, 1997, as amended by Amendment No. 5 filed on March 19, 1997, as amended by Amendment No. 6 filed on March 25, 1999, as amended by Amendment No. 7 filed on March 30, 2000, as amended by Amendment No. 8 filed on February 14, 2001, as amended by Amendment No. 9 filed on February 14, 2002, as amended by Amendment No. 10 filed on February 14, 2003, as amended by Amendment No. 11 filed on February 17, 2004, as amended by Amendment No. 12 filed on February 15, 2005, as amended by Amendment No. 13 filed on February 14, 2006, as amended by Amendment No. 14 filed on February 14, 2007, as amended by Amendment No. 15 filed on February 14, 2008, as amended by Amendment No. 16 filed on February 13, 2009, as amended by Amendment No. 17 filed on February 16, 2010, as amended by Amendment No. 18 filed on February 14, 2011, as amended by Amendment No. 19 filed on February 14, 2012 and as amended by Amendment No. 20 filed on February 14, 2013, (collectively, the “Filings”), related to shares of Class B common stock (“Class B Common”) of NACCO Industries, Inc. (the “Company”) held by certain signatories to the Stockholders’ Agreement, dated as of March 15, 1990, as amended and restated on September 28, 2012, among the signatories thereto, the Company and PNC Bank, NA, as depository, is hereby further amended as follows. Capitalized terms used herein but not defined herein shall have the meanings assigned to such terms in the Filings.

The statements under the heading Claiborne R. Rankin, Jr., which appear in the Filings, are hereby deleted and replaced by the following:

Claiborne R. Rankin, Jr.. Mr. Rankin’s address is 600 W. Drummond #308, Chicago, IL 60619. He is employed in software sales at BrokerSavant, Inc.

The statements under the heading Julia L. Rankin, which appear in the Filings, are hereby deleted and replaced by the following:

Julia L. Rankin. Ms. Rankin’s address is 161 Cushing Street, Cambridge, MA 02138. She is employed as an Education Specialist.

The statements under the heading Jacob A. Kuipers, which appear in the Filings, are hereby deleted and replaced by the following:

Jacob A. Kuipers. Mr. Kuipers’ address is 161 Cushing Street, Cambridge, MA 02138. He is a student.

The information appearing under the heading “Item 5. Interest in Securities of the Issuer,” which appears in the Filings, is hereby amended as follows:

(a) - (b) Although each Reporting Person disclaims beneficial ownership of any shares of Class B Common beneficially owned by each other Reporting Person, pursuant to the Act and regulations thereunder the Reporting Persons may be deemed as a group to have acquired beneficial ownership of 1,542,757 shares of Class B Common, the aggregate number of shares of Class B Common which are subject to the terms of the Stockholders’ Agreement, representing 97.6% of the outstanding Class B Common as of December 31, 2013.

The statements under the heading David B. Williams, which appear in the Filings, are hereby deleted and replaced in their entirety by the following:

David B. Williams. Mr. Williams shares the power to dispose of 767,099 shares of Class B Common, which constitutes approximately 48.5% of the Class B Common outstanding on December 31, 2013.

The statements under the heading John C. Butler, Jr., which appear in the Filings, are hereby deleted and replaced in their entirety by the following:

John C. Butler, Jr. Mr. Butler shares the power to dispose of 767,099 shares of Class B Common, which constitutes approximately 48.5% of the Class B Common outstanding on December 31, 2013.

The statements under the heading Helen R. Butler, which appear in the Filings, are hereby deleted and replaced in their entirety by the following:

Helen R. Butler. Ms. Butler shares the power to dispose of 767,099 shares of Class B Common, which constitutes approximately 48.5% of the Class B Common outstanding on December 31, 2013.

The statements under the heading Clara T. Rankin Williams, which appear in the Filings, are hereby deleted and replaced in their entirety by the following:

Clara T. Rankin Williams. Ms. Williams shares the power to dispose of 767,099 shares of Class B Common, which constitutes approximately 48.5% of the Class B Common outstanding on December 31, 2013.

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SIGNATURES

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

Date: February 14, 2014