PKOH Park Ohio Holdings Corporation

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-279399

PROSPECTUS SUPPLEMENT

(To Prospectus Dated May 23, 2024)

341,997 Shares

Park-Ohio Holdings Corp.

Common Stock

We are offering 341,997 shares of our common stock pursuant to a stock purchase agreement, dated as of August 21, 2024, or the Purchase Agreement, between us and U.S. Bank National Association, as a trustee, or the Trustee, of certain assets of the Park-Ohio Industries, Inc. and Subsidiaries Pension Plan, or the Plan. The Trustee is purchasing the shares of common stock being offered hereby on behalf of the Plan. The shares of common stock are being offered at a price per share of $29.24.

Our common stock is traded on The Nasdaq Stock Market LLC, or Nasdaq, under the symbol “PKOH.” On August 21, 2024, the last reported sale price of our common stock on Nasdaq was $29.24 per share.

Investing in our common stock involves certain risks. Please read carefully the section titled “Risk Factors” beginning on page S-3 of this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The shares of common stock are expected to be delivered on or about August 23, 2024.

The date of this prospectus supplement is August 21, 2024.

TABLE OF CONTENTS

Prospectus Supplement

Prospectus

We have not authorized any dealer, salesperson or other person to give any information or to make any representation other than those contained in or incorporated by reference into this prospectus supplement, the accompanying prospectus or any free writing prospectus that we may provide to you. You must not rely upon any information or representation not contained in or incorporated by reference into this prospectus supplement, the accompanying prospectus or any free writing prospectus that we may provide to you. This prospectus supplement, the accompanying prospectus and any such free writing prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the registered securities to which they relate. Nor do this prospectus supplement, the accompanying prospectus or any such free writing prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation in such jurisdiction. You should not assume that the information contained in this prospectus supplement, the accompanying prospectus, the documents incorporated herein and therein by reference and any such free writing prospectus is correct on any date after their respective dates, even though this prospectus supplement, the accompanying prospectus and any such free writing prospectus are delivered or securities are sold on a later date. Our business, financial condition, results of operations and cash flows may have changed since those dates.

ABOUT THIS PROSPECTUS SUPPLEMENT

This document is in two parts. The first part is this prospectus supplement, which describes the terms of the offering of shares of our common stock under the Purchase Agreement. The second part is the accompanying prospectus, dated May 23, 2024, which we refer to as the accompanying prospectus. Generally, when we refer to this prospectus, we are referring to both this prospectus supplement and the accompanying prospectus, combined. The accompanying prospectus gives more general information, some of which may not apply to the common stock. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or any document that has previously been filed and is incorporated by reference into this prospectus, on the other hand, the information in this prospectus supplement shall control.

Before you invest in our common stock, you should carefully read the registration statement (including the exhibits thereto) of which this prospectus forms a part, this prospectus and the documents incorporated by reference into this prospectus. The documents incorporated by reference are described in this prospectus supplement under “Where You Can Find Additional Information” and “Incorporation of Certain Information by Reference.”

References in this prospectus to the terms “we,” “us” or “our” or other similar terms mean Park-Ohio Holdings Corp. and its consolidated subsidiaries, unless we state otherwise or the context indicates otherwise.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the Securities and Exchange Commission, or the SEC. The SEC maintains an Internet website that contains reports, proxy and information statements and other information regarding issuers, including us, that file electronically with the SEC. The address for the SEC’s website is www.sec.gov.

We make available, free of charge, on our website at www.pkoh.com, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports and statements as soon as reasonably practicable after they are filed with the SEC. The contents of our website are not part of this prospectus, and the reference to our website does not constitute incorporation by reference into this prospectus of the information contained at that site, other than documents we file with the SEC that are incorporated by reference into this prospectus.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information contained in documents that we file with the SEC, which means that we can disclose important information to you by referring to those documents. The information incorporated by reference is an important part of this prospectus. Any statement contained in this prospectus or a document that is incorporated by reference into this prospectus is automatically updated and superseded if information contained in this prospectus, or information that we later file with the SEC, modifies or replaces that information. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the following documents that we filed, excluding any information contained therein or attached as an exhibit thereto that has been furnished, but not filed, with the SEC:

We also incorporate by reference each of the documents that we file with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, or the Exchange Act, after the date of this prospectus until the offering of the shares of our common stock to which this prospectus relates terminates. We will not, however, incorporate by reference in this prospectus any documents or portions of any documents that are not deemed “filed” with the SEC, including any information furnished pursuant to Item 2.02 or Item 7.01 of our Current Reports on Form 8-K unless, and except to the extent, specified in such Current Reports on Form 8-K.

To receive a free copy of any of the documents incorporated by reference into this prospectus (other than exhibits, unless they are specifically incorporated by reference in any such documents), call or write to Park-Ohio Holdings Corp., 6065 Parkland Boulevard, Cleveland, Ohio 44124, Attention: General Counsel, at telephone number (440) 947-2000.

You should not assume that the information contained in this prospectus and the documents incorporated into this prospectus by reference is correct on any date after their respective dates, even though this prospectus is delivered, or securities are sold, on a later date.

DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

Some of the statements contained in this prospectus or incorporated by reference into this prospectus are forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act and are subject to the safe harbor created by the Securities Litigation Reform Act of 1995. These forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance and achievements, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. These uncertainties and other factors include such things as:

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Any forward-looking statement speaks only as of the date on which such statement is made, and we undertake no obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. In light of these and other uncertainties, the inclusion of a forward-looking statement herein should not be regarded as a representation by us that our plans and objectives will be achieved.

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RISK FACTORS

An investment in our common stock involves a high degree of risk. You should carefully consider any risk factors set forth under the heading “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023. You should also refer to the other information in this prospectus, including our financial statements and the related notes incorporated by reference into this prospectus. Additional risks and uncertainties that are not yet identified may also materially harm our business, operating results and financial condition. If any of these risks actually occurs, our business, results of operations and financial condition could suffer. In that case, the trading price of our securities could decline, and you could lose all or part of your investment.

USE OF PROCEEDS

We estimate that the net proceeds from the sale of shares of our common stock offered hereby will be approximately $9,950,000, after deducting the estimated offering expenses payable by us.

We intend to use the net proceeds received upon the sale of shares of our common stock offered hereby for working capital and general corporate purposes. General corporate purposes may include repayment of debt, acquisitions, investments, additions to working capital, capital expenditures and advances to or investments in our subsidiaries. Pending any specific application, we may invest net proceeds in short-term marketable securities or apply them to the reduction of short-term debt.

PLAN OF DISTRIBUTION

We have entered into the Purchase Agreement with the Trustee of the Plan in connection with the offering contemplated by this prospectus supplement. Subject to the terms and conditions of the Purchase Agreement, the Trustee agreed to purchase, on behalf of the Plan, and we agreed to sell, an aggregate of 341,997 shares of our common stock, as provided on the cover page of this prospectus supplement. We believe the Trustee will hold the shares in the Plan pursuant to the Plan’s investment guidelines. The shares of our common stock are expected to be delivered in book-entry form on or about August 23, 2024. No underwriters or agents were engaged for this transaction. We estimate the total expenses of this offering that will be payable by us will be approximately $50,000. The offer and sale of our common stock pursuant to the Purchase Agreement is registered pursuant to our shelf registration statement on Form S-3 (File No. 333-279399) of which this prospectus supplement forms a part. Our common stock is traded on Nasdaq under the symbol “PKOH.” On August 21, 2024, the last reported sale price of our common stock on Nasdaq was $29.24 per share.

LEGAL MATTERS

The legality of the shares of our common stock offered hereby and certain other legal matters will be passed upon for us by Jones Day.

EXPERTS

The consolidated financial statements of Park-Ohio Holdings Corp. appearing in Park-Ohio Holdings Corp.’s Annual Report on Form 10-K for the year ended December 31, 2023 and the effectiveness of Park-Ohio Holdings Corp.’s internal control over financial reporting as of December 31, 2023 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements and Park-Ohio Holdings Corp.’s management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2023 are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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PROSPECTUS

$125,000,000

Debt Securities

Common Stock

of

Park-Ohio Holdings Corp.

We may offer and sell from time to time our debt securities and shares of our common stock. We may sell any combination of these securities in one or more offerings with an aggregate initial offering price of $125,000,000 or the equivalent amount in other currencies or currency units.

We will provide the specific terms of the securities to be offered in one or more supplements to this prospectus. You should read this prospectus and any applicable prospectus supplement carefully before you invest in our securities. This prospectus may not be used to offer and sell our securities unless accompanied by a prospectus supplement describing the method and terms of the offering of those offered securities.

We may offer our securities through agents, underwriters or dealers or directly to investors. Each prospectus supplement will provide the amount, price and terms of the plan of distribution relating to the securities to be sold pursuant to such prospectus supplement. We will set forth the names of any underwriters or agents in the accompanying prospectus supplement, as well as the net proceeds we expect to receive from such sale. In addition, the underwriters, if any, may over-allot a portion of the securities.

Our common stock is traded on The Nasdaq Stock Market LLC under the symbol “PKOH.” On May 13, 2024, the last reported sale price of our common stock on The Nasdaq Stock Market LLC was $26.35 per share. None of the other securities that we may offer under this prospectus are currently publicly traded.

Investing in our securities involves certain risks. Please read carefully the section titled “Risk Factors” beginning on page 4 of this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 23, 2024

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the “SEC”) using a “shelf” registration process. Under this shelf registration process, we may from time to time sell any combination of the securities described in this prospectus in one or more offerings up to a total dollar amount of $125,000,000 or the equivalent amount in other currencies or currency units.

This prospectus provides you with a general description of the securities we may offer. Each time we sell securities, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. The prospectus supplement may also add, update or change information contained in this prospectus. You should read both this prospectus and any applicable prospectus supplement together with additional information under the heading “Where You Can Find Additional Information” and “Incorporation of Certain Information By Reference.”

You should rely only on the information contained or incorporated by reference in this prospectus and in any applicable prospectus supplement. We have not authorized anyone to provide you with different information. You should not assume that the information contained in this prospectus, any applicable prospectus supplement, or any document incorporated by reference is accurate as of any date other than the date mentioned on the cover page of these documents. We are not making offers to sell the securities in any jurisdiction in which an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer or solicitation.

References in this prospectus to the terms “we,” “us” or “our” or other similar terms mean Park-Ohio Holdings Corp. and its consolidated subsidiaries, unless we state otherwise or the context indicates otherwise.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains an Internet website that contains reports, proxy and information statements and other information regarding issuers, including us, that file electronically with the SEC. The address for the SEC’s website is www.sec.gov.

We make available, free of charge, on our website at www.pkoh.com, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports and statements as soon as reasonably practicable after they are filed with the SEC. The contents of our website are not part of this prospectus, and the reference to our website does not constitute incorporation by reference into this prospectus of the information contained at that site, other than documents we file with the SEC that are incorporated by reference into this prospectus.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” into this prospectus the information in documents we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be a part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in or omitted from this prospectus or any accompanying prospectus supplement, or in any other subsequently filed document which also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such

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statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below and any future documents that we file with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (1) after the date of the initial filing of the registration statement of which this prospectus forms a part prior to the effectiveness of the registration statement and (2) after the date of this prospectus until the offering of the securities is terminated. We do not, however, incorporate by reference in this prospectus any documents or portions thereof that are not deemed “filed” with the SEC, including any information furnished pursuant to item 2.02 or item 7.01 of our current reports on Form 8-K after the date of this prospectus unless, and except to the extent, specified in such current reports.

You may obtain copies of these filings without charge by requesting the filings in writing or by telephone at the following address:

Park-Ohio Holdings Corp.

6065 Parkland Boulevard

Cleveland, Ohio 44124

(440) 947-2000

Attention: General Counsel

We have filed with the SEC a registration statement on Form S-3 under the Securities Act of 1933 (the “Securities Act”) covering the securities to be offered and sold by this prospectus and any applicable prospectus supplement. This prospectus does not contain all of the information included in the registration statement, some of which is contained in exhibits to the registration statement. The registration statement, including the exhibits, can be read at the SEC website or at the SEC offices referred to above. Any statement made in this prospectus or any applicable prospectus supplement concerning the contents of any contract, agreement or other document is only a summary of the actual contract, agreement or other document. If we have filed any contract, agreement or other document as an exhibit to the registration statement, you should read the exhibit for a more complete understanding of the document or matter involved. Each statement regarding a contract, agreement or other document is qualified in its entirety by reference to the actual document.

DISCLOSURE REGARDING FORWARD-LOOKING STATEMENTS

Some of the statements contained in this prospectus and any accompanying prospectus supplement or incorporated by reference into this prospectus and any accompanying prospectus supplement are forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act and are subject to the safe harbor created by the Securities Litigation Reform Act of 1995. These forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance and achievements, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. These uncertainties and other factors include such things as:

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Any forward-looking statement speaks only as of the date on which such statement is made, and we undertake no obligation to update any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law. In light of these and other uncertainties, the inclusion of a forward-looking statement herein should not be regarded as a representation by us that our plans and objectives will be achieved.

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OUR BUSINESS

We were incorporated as an Ohio corporation in 1998. Operating primarily through the subsidiaries owned by our direct subsidiary, Park-Ohio Industries, Inc., we are a diversified international company providing world-class customers with a supply chain management outsourcing service, capital equipment used on their production lines, and manufactured components used to assemble their products. We operate our business through three reportable segments: Supply Technologies, Assembly Components and Engineered Products.

Our principal executive office is located at 6065 Parkland Boulevard, Cleveland, Ohio 44124, and our telephone number is (440) 947-2000. Our website address is http://www.pkoh.com. Information contained on or accessible through our website is not a part of this prospectus other than documents we file with the SEC that are specifically incorporated by reference into this prospectus.

RISK FACTORS

An investment in our securities involves a high degree of risk. You should carefully consider any risk factors contained in any applicable prospectus supplement, as well as the risk factors set forth in our most recently filed Annual Report on Form 10-K and any material changes to those risk factors set forth in a Quarterly Report on Form 10-Q. You should also refer to the other information in this prospectus and any applicable prospectus supplement, including our financial statements and the related notes incorporated by reference into this prospectus. Additional risks and uncertainties that are not yet identified may also materially harm our business, operating results and financial condition. If any of these risks actually occurs, our business, results of operations and financial condition could suffer. In that case, the trading price of our securities could decline, and you could lose all or part of your investment.

USE OF PROCEEDS

Unless otherwise indicated in any applicable prospectus supplement or other offering materials, we intend to use the net proceeds from the sale of our securities to which this prospectus relates for general corporate purposes. General corporate purposes may include repayment of debt, acquisitions, investments, additions to working capital, capital expenditures and advances to or investments in our subsidiaries. Pending any specific application, we may invest net proceeds in short-term marketable securities or apply them to the reduction of short-term debt.

DESCRIPTION OF DEBT SECURITIES

The following description sets forth certain general terms and provisions of the debt securities that we may issue, which may be issued as convertible or exchangeable debt securities. We will set forth the particular terms of the debt securities we offer in a prospectus supplement and the extent, if any, to which the following general terms and provisions will apply to particular debt securities.

The debt securities will be issued under an indenture to be entered into between us and a trustee to be named in a prospectus supplement. The indenture, and any supplemental indentures thereto, will be subject to, and governed by, the Trust Indenture Act of 1939, as amended. The following description of general terms and provisions relating to the debt securities and the indenture under which the debt securities will be issued is a summary only and therefore is not complete and is subject to, and qualified in its entirety by reference to, the terms and provisions of the indenture. The form of the indenture has been filed with the SEC as an exhibit to the registration statement, of which this prospectus forms a part, and you should read the indenture for provisions that may be important to you. For more information on how you can obtain a copy of the form of the indenture, see “Where You Can Find More Information.”

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Capitalized terms used in this section and not defined herein have the meanings specified in the indenture. When we refer to “Park-Ohio,” “we,” “our” and “us” in this section, we mean Park-Ohio Holdings Corp. excluding, unless the context otherwise requires or as otherwise expressly stated, its subsidiaries.

General

Unless otherwise specified in a prospectus supplement, the debt securities will be our direct, unsecured obligations and will rank equally with all of our existing and future senior unsecured indebtedness senior in right of payment to all of our subordinated indebtedness.

The indenture does not limit the aggregate principal amount of debt securities that may be issued under it and provides that debt securities may be issued under it from time to time in one or more series. We may specify a maximum aggregate principal amount for the debt securities of any series.

Unless otherwise specified in the applicable prospectus supplement, the indenture does not afford the holders of the debt securities the right to require us to repurchase or redeem the debt securities in the event of a highly-leveraged transaction.

We are not obligated to issue all debt securities of one series at the same time and, unless otherwise provided in the applicable prospectus supplement, we may reopen a series, without the consent of the holders of the outstanding debt securities of that series, for the issuance of additional debt securities of that series. Additional debt securities of a particular series will have the same terms and conditions as outstanding debt securities of such series, except for the issue date and, in some cases, the public offering price and the first interest payment date, and will be consolidated with, and form a single series with, such outstanding debt securities; provided, however, that if such additional debt securities are not fungible with the outstanding debt securities of such series for U.S. federal income tax purposes, the additional debt securities will have a separate CUSIP number.

We will set forth in a prospectus supplement relating to any debt securities being offered, the aggregate principal amount and the following terms of the debt securities, if applicable:

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The foregoing is not intended to be an exclusive list of the terms that may be applicable to any offered debt securities.

In addition, the indenture does not limit our ability to issue convertible, exchangeable or subordinated debt securities. Any conversion, exchange or subordination provisions of debt securities will be described in the relevant prospectus supplement. Such terms may include provisions for conversion or exchange, either mandatory, at the option of the holder or at our option, in which case the number of shares of common stock or other securities to be received by the holders of debt securities would be calculated as of a time and in the manner stated in the prospectus supplement.

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the U.S. federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

If we denominate the purchase price of any of the debt securities in a foreign currency or currencies or a foreign currency unit or units, or if the principal of and any premium and interest on any series of debt securities is payable in a foreign currency or currencies or a foreign currency unit or units, we will provide you with information on the restrictions, elections, general tax considerations, specific terms and other information with respect to that issue of debt securities and such foreign currency or currencies or foreign currency unit or units in the applicable prospectus supplement.

Exchange and Transfer

Debt securities may be transferred or exchanged at the office of the registrar or co-registrar designated by us.

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We will not impose a service charge for any transfer or exchange, but we may require holders to pay any tax or other governmental charges associated with any transfer or exchange. In the event of any redemption of debt securities of any series, we will not be required to:

We may initially appoint the trustee as the registrar. Any transfer agent, in addition to the registrar initially designated by us, will be named in the prospectus supplement. We may designate additional transfer agents or change transfer agents or change the office of the transfer agent. However, we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

Global Securities

The debt securities of any series may be represented, in whole or in part, by one or more global securities. Each global security will:

No global security may be exchanged in whole or in part for debt securities registered in the name of any person other than the depositary or any nominee unless:

As long as the depositary, or its nominee, is the registered owner of a global security, the depositary or nominee will be considered the sole owner and holder of the debt securities represented by the global security for all purposes under the indenture. Except in the above limited circumstances, owners of beneficial interests in a global security:

Payments on a global security will be made to the depositary or its nominee as the holder of the global security. Some jurisdictions have laws that require that certain purchasers of securities take physical delivery of such securities in definitive form. These laws may impair the ability to transfer beneficial interests in a global security.

Institutions that have accounts with the depositary or its nominee are referred to as “participants.” Ownership of beneficial interests in a global security will be limited to participants and to persons that may hold beneficial

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interests through participants. The depositary will credit, on its book-entry registration and transfer system, the respective principal amounts of debt securities represented by the global security to the accounts of its participants. Each person owning a beneficial interest in a global security must rely on the procedures of the depositary (and, if such person is not a participant, on procedures of the participant through which such person owns its interest) to exercise any rights of a holder under the indenture.

Ownership of beneficial interests in a global security will be shown on and effected through records maintained by the depositary, with respect to participants’ interests, or by any participant, with respect to interests of persons held by participants on their behalf. Payments, transfers and exchanges relating to beneficial interests in a global security will be subject to policies and procedures of the depositary. The depositary’s policies and procedures may change from time to time. Neither we nor the trustee will have any responsibility or liability for the depositary’s acts or omissions or any participant’s records with respect to beneficial interests in a global security.

Payment and Paying Agent

The provisions of this subsection will apply to the debt securities unless otherwise indicated in the prospectus supplement. Payment of interest on a debt security on any interest payment date will be made to the person in whose name the debt security is registered at the close of business on the regular record date. Payment on debt securities of a particular series will be payable at the office of a paying agent or paying agents designated by us. However, at our option, we may pay interest by mailing a check to the record holder.

We may also name any other paying agents in the prospectus supplement. We may designate additional paying agents, change paying agents or change the office of any paying agent. However, we will be required to maintain a paying agent in each place of payment for the debt securities of a particular series.

Subject to any applicable abandoned property law, all moneys paid by us to a paying agent for payment on any debt security that remain unclaimed at the end of two years after such payment was due will be repaid to us. Thereafter, the holder may look only to us for such payment.

Consolidation, Merger and Sale of Assets

Except as otherwise set forth in the applicable prospectus supplement, we may not merge or consolidate with or into any other person, in a transaction in which we are not the surviving corporation, or sell, convey, transfer, lease or otherwise dispose of all or substantially all of the properties and assets of us and our subsidiaries, taken as a whole, to any person, unless:

In the event of the above transaction, if there is a successor or transferee, then the successor or transferee will expressly assume all of our obligations under the indenture and automatically be substituted for us in the indenture and as issuer of the debt securities and may exercise every right and power of ours under the indenture with the same effect as if such successor or transferee had been named in our place in the indenture; provided, however, that the predecessor company will not be relieved of the obligation to pay principal and interest on the debt securities except in the case of a sale of all of the assets of us and our subsidiaries.

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Events of Default

Event of default means, with respect to any series of debt securities, any of the following:

We will promptly deliver to the trustee written notice of any event which with the giving of notice and the lapse of time would become a covenant event of default, or any other event of default provided with respect to debt securities of that series that is described in the applicable prospectus supplement, along with a description of the status and what action we are taking or propose to take with respect to such event of default.

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of an event of default may constitute an event of default under our bank credit agreements in existence from time to time. In addition, the occurrence of certain events of default or an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization of our company) with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of, and accrued and unpaid interest, if any, on all debt securities of that series. In the case of an event of default resulting from certain events of bankruptcy, insolvency or reorganization of our company, the principal (or such specified amount) of and accrued and unpaid interest, if any, on all outstanding debt securities will become and be immediately due and payable without any declaration or other act on the part of the trustee or any holder of outstanding debt securities. At any time after a declaration of acceleration with respect to debt securities of any series has been made, the holders of a majority in aggregate principal amount of the outstanding debt securities of that series may rescind and annul the acceleration if the rescission and annulment would not conflict with any judgment or decree already rendered and if all events of default with respect to that series, other than the non-payment of principal and interest, if any, with respect to debt securities of that series that has become due and payable solely because of the acceleration, have been cured or waived and all sums paid or advanced by the trustee and the reasonable compensation expenses and disbursements of the trustee and its agents and counsel have been paid as provided in the indenture.

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The indenture provides that the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any holder of outstanding debt securities, unless the trustee receives security or indemnity satisfactory to it against any loss, liability or expense. Subject to certain rights of the trustee, the holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or exercising any trust or power conferred on the trustee with respect to the debt securities of that series.

No holder of any debt security of any series will have any right to institute any proceeding, judicial or otherwise, with respect to the indenture or for the appointment of a receiver or trustee, or for any remedy under the indenture, unless:

Notwithstanding the foregoing, the holder of any debt security will have an absolute and unconditional right to receive payment of the principal of, and premium and any interest on, that debt security on or after the due dates expressed in that debt security and to institute suit for the enforcement of such payment.

The indenture requires us, within 120 days after the end of our fiscal year, to furnish to the trustee a statement as to compliance with the indenture. The indenture provides that the trustee may withhold notice to the holders of debt securities of any series of any default or event of default (except in payment on any debt securities of that series) with respect to debt securities of that series if it in good faith determines that withholding notice is in the interest of the holders of those debt securities.

Modification and Waiver

We may amend or modify the indenture without the consent of any holder of debt securities of the series affected by the modifications or amendments in order to:

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Other amendments and modifications of the indenture or the debt securities issued may be made with the consent of the holders of at least a majority of the aggregate principal amount of the outstanding debt securities of the affected series, and our compliance with any provision of the indenture with respect to the debt securities may be waived by written notice to the trustee by the holders of a majority of the aggregate principal amount of the outstanding debt securities of the affected series. However, no modification or amendment may, without the consent of the holder of each outstanding debt security of the affected series:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of an affected series may, on behalf of the holders of all debt securities of such series, waive our compliance with provisions of the indenture. Prior to the acceleration of the maturity of the debt securities of any series pursuant to the terms of the indenture, the holders of a majority in aggregate principal amount of the outstanding debt securities of such series may, on behalf of the holders of all the debt securities of such series, waive any past default under the indenture with respect to such debt securities and its consequences, except (i) a default with respect to such series in the payment of the principal of, or premium or any interest on, the debt securities of such series or (ii) a default or event of default in respect of a covenant or provision that cannot be modified or amended without the consent of all of the holders of the outstanding debt securities of the affected series.

Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

Legal Defeasance. The indenture provides that, in certain circumstances, we may be discharged from any and all obligations in respect of the debt securities of any series (except for certain obligations to register the transfer or exchange of debt securities, to replace stolen, lost or mutilated debt securities, and to maintain paying agencies and certain provisions relating to the treatment of funds held by paying agents). We will be so discharged upon the deposit with the trustee, in trust, of money and/or U.S. government obligations that, through the payment of interest and principal in accordance with their terms, will provide money in an amount sufficient in the written opinion of a nationally recognized firm of independent public accountants, a nationally recognized investment bank or a nationally recognized appraisal firm to pay and discharge each installment of principal, premium and interest in accordance with the terms of the indenture and the debt securities of that series.

This discharge may occur only if, among other things, we have delivered to the trustee an opinion of counsel stating that we have received from, or there has been published by, the United States Internal Revenue Service a ruling or, since the date of execution of the indenture, there has been a change in the applicable U.S. federal

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income tax law, in either case to the effect that, and based thereon such opinion shall confirm that, the beneficial owners of the debt securities of the applicable series will not recognize income, gain or loss for U.S. federal income tax purposes as a result of the deposit, defeasance and discharge and will be subject to U.S. federal income tax on the same amounts and in the same manner and at the same times as would have been the case if the deposit, defeasance and discharge had not occurred.

Defeasance of Certain Covenants. The indenture provides that, upon compliance with certain conditions, we may be released from our obligation to comply with certain covenants set forth in the indenture and any supplemental indenture, and any failure to comply with those covenants will not constitute a default or an event of default with respect to the debt securities of the applicable series, or covenant defeasance. If we exercise our covenant defeasance option with respect to a series of debt securities, payment of such debt securities may not be accelerated because of an event of default related to certain events of bankruptcy, insolvency or reorganization of our significant subsidiaries.

The conditions include:

Governing Law

The indenture and the debt securities will be governed by, and construed in accordance with, the internal laws of the State of New York.

DESCRIPTION OF COMMON STOCK

We are authorized to issue 40,000,000 shares of common stock, par value $1.00 per share, and 632,470 shares of serial preferred stock, par value $1.00 per share.

Common Stock

This section describes the general terms and provisions of our common stock. For more detailed information, you should refer to our Amended and Restated Articles of Incorporation (“Articles”) and Code of Regulations (“Regulations”), copies of which have been filed with the SEC. These documents are also incorporated by reference into the registration statement of which this prospectus forms a part.

Subject to the rights of any holders of serial preferred stock, each outstanding share of common stock is entitled to such dividends as may be declared from time to time by our board of directors. Each outstanding share of common stock is entitled to one vote on all matters submitted to a vote of shareholders. Pursuant to our Articles, holders of our common stock do not have the right to cumulative voting; therefore, the holders of a majority of the shares voting for the election of the board of directors can elect all the directors standing for election, if they so choose. In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to receive, on a pro rata basis, any assets remaining after provision for payment of creditors and any holders of our serial preferred stock.

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No holder of our common stock has any preemptive or preferential right to purchase or subscribe to any of our shares of any class, except to the extent provided by our board of directors.

Serial Preferred Stock

This section describes the general terms and provisions of our serial preferred stock. For more detailed information, you should refer to our Articles and Regulations, copies of which have been filed with the SEC. These documents are also incorporated by reference into the registration statement of which this prospectus forms a part.

Our Articles authorize our board of directors to issue the serial preferred stock as serial stock of any series and, in connection with the creation of such series, to fix by the resolution or resolutions providing for the issue of shares the voting powers and designations, preferences and relative, participating, optional or other special rights, and qualifications, limitations or restrictions of such series, to the fullest extent permitted by the laws of the State of Ohio.

Certain Anti-takeover Provisions of Ohio Law

Certain provisions of Ohio law may have the effect of discouraging or rendering more difficult an unsolicited acquisition of a corporation or its capital stock to the extent the corporation is subject to those provisions. We have opted out of one such provision. We remain subject to the remaining provisions, which are described below.

Chapter 1704 of the Ohio Revised Code prohibits certain transactions, including mergers, sales of assets, issuances or purchases of securities, liquidation or dissolution, or reclassifications of the then-outstanding shares of an Ohio corporation with 50 or more shareholders involving, or for the benefit of, certain holders of shares representing 10% or more of the voting power of the corporation, any such shareholder a 10% Shareholder, unless:

Chapter 1704 of the Ohio Revised Code may have the effect of deterring certain potential acquisitions of us that might be beneficial to shareholders.

Section 1707.041 of the Ohio Revised Code regulates certain “control bids” for corporations in Ohio with certain concentrations of Ohio shareholders and permits the Ohio Division of Securities to suspend a control bid if certain information is not provided to offerees.

Listing

Our common stock is quoted on The Nasdaq Stock Market LLC under the symbol “PKOH.”

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PLAN OF DISTRIBUTION

We may sell the offered securities in and outside the United States:

Any applicable prospectus supplement will include the following information:

Sale through Underwriters or Dealers

If underwriters are used in the sale, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer the securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in any applicable prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include over-allotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters may also impose a penalty bid, which means that selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if the offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, the underwriters may discontinue these activities at any time.

Some or all of the securities that we offer though this prospectus may be new issues of securities with no established trading market. Any underwriters to whom we sell our securities for public offering and sale may

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make a market in those securities, but they will not be obligated to do so and they may discontinue any market making at any time without notice. Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities that we offer.

If dealers are used in the sale of the securities, we will sell the securities to them as principals. They may then resell the securities to the public at varying prices determined by the dealers at the time of resale. We will include in any applicable prospectus supplement the names of the dealers and the terms of the transaction.

Direct Sales and Sales through Agents

We may sell the securities directly. In this case, no underwriters or agents would be involved. We may also sell the securities through agents designated from time to time. In any applicable prospectus supplement, we will name any agent involved in the offer or sale of the offered securities and we will describe any commissions payable to the agent. Unless we inform you otherwise in any applicable prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any sales of these securities in any applicable prospectus supplement.

Remarketing Arrangements

Offered securities may also be offered and sold, if so indicated in any applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us. Any remarketing firm will be identified and the terms of its agreements, if any, with us and its compensation will be described in any applicable prospectus supplement.

Delayed Delivery Contracts

If we so indicate in any applicable prospectus supplement, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in any applicable prospectus supplement. Any applicable prospectus supplement will describe the commission payable for solicitation of those contracts.

General Information

We may have agreements with the agents, dealers, underwriters and remarketing firms to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers, underwriters or remarketing firms may be required to make. Agents, dealers, underwriters and remarketing firms may be customers of, engage in transactions with or perform other services for us in the ordinary course of their businesses.

LEGAL MATTERS

Jones Day will pass upon the validity of the securities being offered hereby. Any underwriters may be advised about legal matters by their own counsel, who will be named in the applicable prospectus supplement.

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EXPERTS

The consolidated financial statements of Park-Ohio Holdings Corp. appearing in Park-Ohio Holdings Corp.’s Annual Report on Form 10-K for the year ended December 31, 2023 and the effectiveness of Park-Ohio Holdings Corp.’s internal control over financial reporting as of December 31, 2023 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements and Park-Ohio Holdings Corp.’s management’s assessment of the effectiveness of internal control over financial reporting as of December 31, 2023 are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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341,997 Shares

Park-Ohio Holdings Corp.

Common Stock

PROSPECTUS SUPPLEMENT

August 21, 2024