PH Parker Hannifin Corp

Exhibit 4.1

EXECUTION VERSION

PARKER-HANNIFIN CORPORATION OFFICER’S CERTIFICATE

ESTABLISHING TERMS OF NOTES UNDER AN OPEN-ENDED INDENTURE

Todd M. Leombruno, Executive Vice President and Chief Financial Officer of Parker-Hannifin Corporation, an Ohio corporation (the “Company”), does hereby certify in accordance with Sections 201 and 301 of the Indenture, dated as of September 5, 2023 (the “Indenture”), with The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”), as follows (capitalized terms used herein and not otherwise defined herein are used with the same meanings ascribed to such terms in the Indenture):

Principal, Interest and Maturity

Payment will be made upon presentation of the Notes at the office of the Paying Agent, currently at 125 Old Broad Street, Fifth Floor, London, EC2N 1AR, United Kingdom; provided, however, that payment of interest may be made at the Company’s option by check mailed to the registered holder on the applicable record date at such address as shall appear in the security register or by wire transfer of immediately available funds to an account

specified in writing by such holder to the Company, the Paying Agent and the trustee prior to the relevant record date. So long as the Notes are in book-entry form registered in the name of the nominee of the Common Safekeeper and held by the Common Safekeeper, the Company will make payments of principal and interest to the Common Safekeeper whose nominee is the registered holder of the Global Notes.

Interest payable on any Interest Payment Date for the Notes, any redemption date for the Notes or the maturity date for the Notes will be the amount of interest accrued from, and including, the preceding Interest Payment Date for the Notes in respect of which interest has been paid or duly provided for (or from and including the original issue date, if no interest has been paid or duly provided for with respect to the Notes) to, but excluding, such Interest Payment Date, redemption date or maturity date, as the case may be. This payment convention is referred to as ACTUAL/ACTUAL (ICMA) as defined in the rulebook of the International Capital Markets Association. If any Interest Payment Date, redemption date or maturity date falls on a day that is not a Business Day, the payment otherwise required to be made on such date will be made on the next succeeding Business Day, and the Company will not be liable for any additional interest as a result of the delay in payment. If a redemption date or maturity date falls on a day that is not a Business Day, the related payment of principal and interest will be made on the next succeeding Business Day, and no interest will accrue on the amounts so payable for the period from and after such date to the next succeeding Business Day.

Issuance in Euro

Initial holders will be required to pay for the Notes in euro, and principal and interest payments in respect of the Notes (including payments made upon any redemption of such Notes) will be payable in euro. The Company has initially appointed as paying agent U.S. Bank Europe DAC, with its registered office at Block F1, Cherrywood Business Park, Cherrywood, Dublin 18, Ireland D18 W2X7, acting through its UK branch from its offices at 125 Old Broad Street, Fifth Floor, London, EC2N 1AR, United Kingdom, under the trade name U.S. Bank Global Corporate Trust.

If euro is unavailable to the Company due to the imposition of exchange controls or other circumstances beyond the Company’s control or if euro is no longer being used by the then member states of the European Monetary Union that have adopted euro as their currency or for the settlement of transactions by public institutions of or within the international banking community, then all payments in respect of the Notes will be made in U.S. dollars until euro is again available to the Company or so used. The amount payable on any date in euro will be converted into U.S. dollars at the rate mandated by the U.S. Federal Reserve Board as of the close of business on the second business day prior to the relevant payment date or, if the U.S. Federal Reserve Board has not mandated a rate of conversion, on the basis of the most recently available market exchange rate for euro. Any payment in respect of the Notes so made in U.S. dollars will not constitute an event of default under the Notes or the Indenture. Neither the trustee nor the Paying Agent shall be responsible for obtaining exchange rates, effecting conversions or otherwise handling redenominations.

Optional Redemption

Prior to February 1, 2030 (one month prior to their maturity date) (the “Par Call Date”), the Company may redeem the Notes at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

plus, in each case, accrued and unpaid interest thereon to the redemption date.

On or after the Par Call Date for the Notes, the Company may redeem the Notes, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest thereon to the redemption date.

For the purposes of the optional redemption provisions of the Notes, the following additional terms will be applicable:

“Comparable Government Bond” means, in relation to any Comparable Government Bond Rate calculation, at the discretion of an independent investment bank selected by the Company, a German government bond whose maturity is closest to the Par Call Date, or if such independent investment bank in its discretion determines that such similar bond is not in issue, such other German government bond as such independent investment bank may, with the advice of three brokers of, and/or market makers in, German government bonds selected by such independent investment bank, determine to be appropriate for determining the Comparable Government Bond Rate.

“Comparable Government Bond Rate” means the price, expressed as a percentage (rounded to three decimal places, 0.0005 being rounded upwards), at which the gross redemption yield on the Notes, if they were to be purchased at such price on the third Business Day prior to the date fixed for redemption, would be equal to the gross redemption yield on such Business Day of the applicable Comparable Government Bond on the basis of the middle market price of such Comparable Government Bond prevailing at 11:00 a.m. (London time) on such Business Day as determined by an independent investment bank selected by the Company.

The Company’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The trustee shall not be responsible for calculating the redemption price or determining the Comparable Government Bond Rate.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the depositary’s procedures) at least 10 days but not more than 60 days before the redemption date to each holder of Notes to be redeemed. Any redemption or notice described above may, at the Company’s discretion, be subject to the satisfaction or waiver of one or more conditions precedent. In addition, if such redemption is subject to satisfaction or waiver of one or more conditions precedent, the notice of such redemption shall state that, in the Company’s discretion, the redemption date may be delayed until such time as any or all such conditions shall be satisfied or waived, or such notice may be rescinded and the redemption terminated in the event that any or all such conditions shall not have been satisfied or waived by the redemption date, or by the redemption date so delayed. The Company shall notify holders of any such rescission as soon as practicable after the Company determines that such conditions precedent will not be able to be satisfied or the Company is not able or willing to waive such conditions precedent.

In the case of a partial redemption, selection of the Notes for redemption will be made pursuant to the applicable depositary’s procedures. No Notes of a principal amount of €100,000 or less will be redeemed in part. If any note is to be redeemed in part only, the notice of redemption that relates to the note will state the portion of the principal amount of the note to be redeemed. A new note in a principal amount equal to the unredeemed portion of the note will be issued in the name of the holder of the note upon surrender for cancellation of the original note. For so long as the Notes are held by Euroclear, Clearstream or another depositary, the redemption of the Notes shall be done in accordance with the policies and procedures of the depositary.

Unless the Company defaults in payment of the redemption price, on and after the redemption date interest will cease to accrue on the Notes or portions thereof called for redemption.

For the avoidance of doubt, neither the Trustee nor any Paying Agent shall be responsible for performing any calculations or selections in connection with any optional redemption.

Payment of Additional Amounts

All payments of principal and interest in respect of the Notes will be made free and clear of, and without deduction or withholding for or on account of, any present or future tax, assessment or other governmental charge required to be deducted or withheld by the United States or a taxing authority in the United States, unless such withholding or deduction is required by law. The Company will, subject to the exceptions and limitations set forth below, pay as additional interest on the Notes such additional amounts as are necessary in order that the net payment by The Company or the Paying Agent of the principal of and interest on the Notes to a holder who is not a United States person (as defined below), after withholding or deduction for any present or future tax, assessment or other governmental charge imposed by the United States or a taxing authority in the United States will not be less than the amount provided in the Notes to be then due and payable; provided, however, that the foregoing obligation to pay additional amounts shall not apply:

Except as specifically provided under this heading “Payment of Additional Amounts,” the Company will not be required to pay additional amounts in respect of any tax, assessment or other governmental charge.

As used under this heading “Payment of Additional Amounts” and under the heading “Redemption for Tax Reasons,” the term “United States” means the United States of America (including the states and the District of Columbia and any political subdivision thereof), and the term “United States person” means (i) any individual who is a citizen or resident of the United States for U.S. federal income tax purposes, (ii) a corporation, partnership or other entity created or organized in or under the laws of the United States (other than a partnership that is not treated as a United States person for U.S. federal income tax purposes), (iii) any estate the income of which is subject to United States federal income taxation regardless of its source, or (iv) any trust if a U.S. court can exercise primary supervision over the administration of the trust and one or more United States persons can control all substantial trust decisions, or if a valid election is in place to treat the trust as a United States person. Any reference in the terms of the Notes to any amounts in respect of the Notes shall be deemed also to refer to any additional amounts which may be payable under this provision.

Redemption for Tax Reasons

If, as a result of any change in, or amendment to, the laws (or any regulations or rulings promulgated under the laws) of the United States (or any taxing authority in the United States), or any change in, or amendment to, an official position regarding the application or interpretation of such laws, regulations or rulings, which change or amendment is announced or becomes effective on or after February 6, 2025, the Company becomes or, based upon a written opinion of independent counsel selected by the Company, will become obligated to pay additional amounts as described herein under the heading “Payment of Additional Amounts” with respect to the Notes, then the Company may at any time at its option redeem, in whole, but not in part, the Notes on not less than 10 nor more than 60 days prior notice, at a redemption price equal to 100% of their principal amount, together with accrued and unpaid interest on the Notes to, but not including, the date fixed for redemption.

Repurchase Upon a Change of Control

If a Change of Control Triggering Event (as defined below) occurs with respect to the Notes, unless the Company has exercised its option to redeem the Notes as described above, the Company will be required to make an offer (a “Change of Control Offer”) to each holder of the Notes to repurchase all or any part (equal to €100,000 or an integral multiple of €1,000 in excess thereof) of that holder’s Notes on the terms set forth in such Notes. In a Change of Control Offer, the Company will be required to offer payment in cash equal to 101% of the aggregate principal amount of Notes repurchased, plus accrued and unpaid interest, if any, on the Notes repurchased to the date of repurchase (a “Change of Control Payment”).

Within 30 days following any such Change of Control Triggering Event or, at the Company’s option, prior to any Change of Control (as defined below), but after public announcement of the transaction that constitutes or may constitute the Change of Control, a notice will be mailed or electronically delivered, or with respect to Notes held in global form, to the extent permitted or required by applicable procedures or regulations of Euroclear and Clearstream, sent electronically to holders of the Notes, with a copy to the Trustee under the Indenture and the Paying Agent that such Notes are being issued under, describing the transaction that constitutes or may constitute the Change of Control Triggering Event and offering to repurchase such Notes on the date specified in the notice, which date will be no earlier than 10 days and (unless delivered in advance of the occurrence of such Change of Control Triggering Event) no later than 60 days from the date such notice is mailed or sent (a “Change of Control Payment Date”). The notice will, if mailed or sent prior to the date of consummation of the Change of Control, state that the Change of Control Offer is conditioned on the Change of Control Triggering Event occurring.

On each Change of Control Payment Date, the Company will, to the extent lawful:

The Company will not be required to make a Change of Control Offer upon the occurrence of a Change of Control Triggering Event if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for a Change of Control Offer made by the Company, and the third party repurchases all Notes properly tendered and not withdrawn under its offer.

The Company will comply with the requirements of Rule 14e-1 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the Notes as a result of a Change of Control Triggering Event. To the extent that the provisions of any such securities laws or regulations conflict with the Change of Control Offer provisions of the Notes, the Company will comply with those securities laws and regulations and will not be deemed to have breached its obligations under the Change of Control Offer provisions of the Notes by virtue of any such conflict.

If holders of not less than 90% in aggregate principal amount of the outstanding Notes validly tender and do not withdraw such Notes in a Change of Control Offer and the Company, or any third party making a Change of Control Offer in lieu of the Company, as described above, purchases all of the Notes validly tendered and not withdrawn by such holders, the Company will have the right, upon not less than 10 nor more than 60 days’ prior notice, given not more than 30 days following such purchase pursuant to the Change of Control Offer described above, to redeem all Notes that remain outstanding following such purchase at a redemption price in cash equal to the applicable Change of Control Payment.

Neither the Trustee nor any Paying Agent shall be responsible for determining whether any Change of Control Triggering Event has occurred and whether any Change of Control Offer with respect to the Notes is required. Neither the Trustee nor any Paying Agent shall be responsible for monitoring the Company’s rating status, making any request upon any Rating Agency, or determining whether any rating event with respect to the Notes has occurred.

For purposes of the Change of Control Offer provisions of the Notes, the following terms will be applicable:

“Change of Control” means the occurrence of any of the following: (1) the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or more related transactions, of all or substantially all of the Company’s assets and the assets of the Company’s subsidiaries, taken as a whole, to any person, other than the Company or one of its subsidiaries; (2) the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any person becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more than 50% of the Company’s outstanding Voting Stock (as defined below), measured by voting power rather than number of shares; (3) the Company consolidates with, or merges with or into, any person, or any person consolidates with, or merges with or into, the Company, in any such event pursuant to a transaction in which any of the Company’s outstanding Voting Stock or the Voting Stock of such other person is converted into or exchanged for cash, securities or other property, other than any such transaction where the shares of the Company’s Voting Stock outstanding immediately prior to such transaction constitute, or are converted into or exchanged for, a majority of the Voting Stock of the surviving person or any direct or indirect parent company of the surviving person, measured by voting power rather than number of shares, immediately after giving effect to such transaction; (4) the first day on which a majority of the members of the Board of Directors are not Continuing Directors; or (5) the adoption of a plan relating to the Company’s liquidation or dissolution. The term “person,” as used in this definition, has the meaning given thereto in Section 13(d)(3) of the Exchange Act.

Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control if (1) the Company becomes a direct or indirect wholly owned subsidiary of a holding company and (2)(A) the direct or indirect holders of the Voting Stock of such holding company immediately following that transaction are substantially the same as the holders of the Company’s Voting Stock immediately prior to that transaction or (B) immediately following that transaction no person (other than a holding company satisfying the requirements of this sentence) is the beneficial owner, directly or indirectly, of more than 50% of the Voting Stock of such holding company.

“Change of Control Triggering Event” means the occurrence of both a Change of Control and a Rating Event.

“Continuing Directors” means, as of any date of determination, any member of the Board of Directors who (1) was a member of such Board of Directors on the date the Notes were issued or (2) was nominated for election, elected or appointed to such Board of Directors with the approval of a majority of the directors who were members of such Board of Directors at the time of such nomination, election or appointment (either by a specific vote or by approval of the Company’s proxy statement in which such member was named as a nominee for election as a director, without objection to such nomination).

“Fitch” means Fitch Ratings Inc., and its successors.

“Investment Grade Rating” means a rating equal to or higher than BBB- (or the equivalent) by Fitch, Baa3 (or the equivalent) by Moody’s, and BBB- (or the equivalent) by S&P, and the equivalent investment grade credit rating from any replacement rating agency or Rating Agencies selected by the Company.

“Moody’s” means Moody’s Investors Service, Inc., and its successors.

“Rating Agencies” means (1) each of Fitch, Moody’s and S&P; and (2) if any of Fitch, Moody’s or S&P ceases to rate the Notes or fails to make a rating of the Notes publicly available for reasons outside of the Company’s control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange Act selected by the Company (as certified by a resolution of the Board of Directors) as a replacement agency for Fitch, Moody’s or S&P, or all of them, as the case may be, with respect to the Notes.

“Rating Event” means the rating on the Notes is lowered by at least two of the three Rating Agencies and the Notes are rated below an Investment Grade Rating by at least two of the three Rating Agencies on any day within the 60-day period (which 60-day period will be extended so long as the rating of the Notes is under publicly announced consideration for a possible downgrade by any of the Rating Agencies) after the earlier of (1) the occurrence of a Change of Control and (2) public notice of the occurrence of a Change of Control or the Company’s intention to effect a Change of Control.

“S&P” means S&P Global Ratings, a division of S&P Global Inc., and its successors.

“Voting Stock” means, with respect to any specified “person” (as that term is used in Section 13(d)(3) of the Exchange Act) as of any date, the capital stock of such person that is at the time entitled to vote generally in the election of the board of directors of such person.

“Business Day” means each Monday, Tuesday, Wednesday, Thursday and Friday (a) which is not a day on which banking institutions are authorized or obligated by law or executive order to close in New York City or London and (b) on which the Trans-European Automated Real-time Gross Settlement Express Transfer system (the TARGET2 system), or any successor thereto, is open.

(Signatures are on the following page.)

IN WITNESS WHEREOF, the undersigned has placed his hand as of this 20th day of February, 2025.

EXHIBIT A

[FORM OF FACE OF NOTE]

[Global Notes Legend]

THE NOTE IS A GLOBAL NOTE WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A NOMINEE OF THE ENTITY APPOINTED AS COMMON SAFEKEEPER (THE “COMMON SAFEKEEPER”) AND WILL BE DEPOSITED WITH THE COMMON SAFEKEEPER FOR EUROCLEAR BANK SA/NV (“EUROCLEAR”) AND CLEARSTREAM BANKING, S.A. (“CLEARSTREAM”). UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE COMMON SAFEKEEPER TO THE COMPANY OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF THE NOMINEE OF THE COMMON SAFEKEEPER OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE COMMON SAFEKEEPER (AND ANY PAYMENT IS MADE TO THE COMMON SAFEKEEPER OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE COMMON SAFEKEEPER), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, THE COMMON SAFEKEEPER OR ITS NOMINEES, HAS AN INTEREST HEREIN.

TRANSFERS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF THE COMMON SAFEKEEPER OR TO A SUCCESSOR THEREOF OR SUCH SUCCESSOR’S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL NOTE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE INDENTURE REFERRED TO ON THE REVERSE HEREOF.

[FORM OF NOTE]

2.900% Senior Notes due 2030

ISIN: XS2986378714

Common Code: 298637871

This certifies that the person whose name is entered in the register maintained by the Registrar in relation to the Notes (the “Register”) is the duly registered holder (the “Holder”) of Notes in the aggregate principal amount of €700,000,000 or such other amount as is shown on Register as being represented by this Global Note and is duly endorsed (for information purposes only) in the fourth column of the Schedule of Increases or Decreases in Note attached to this Global Note.

Parker-Hannifin Corporation, a corporation duly organized and existing under the laws of Ohio, promises to pay to each Holder the aggregate principal amount shown on the Register as being represented by this Global Note on March 1, 2030 (the “Stated Maturity Date”) (unless redeemed on any day fixed for redemption prior to the Stated Maturity Date in accordance with the terms of this Note and the Indenture).

Interest Payment Dates: March 1 of each year, commencing March 1, 2026

Issue Date: February 20, 2025

Record Dates: Business Day immediately preceding the Interest Payment Date

Additional provisions of this Note are set forth on the other side of this Note.

This Global Note shall not be valid unless authenticated by the Trustee and effectuated by the entity appointed as Common Safekeeper by Clearstream.

IN WITNESS WHEREOF, the parties have caused this instrument to be duly executed.

TRUSTEE’S CERTIFICATE OF AUTHENTICATION

This is one of the Notes referred to in the Indenture.

Dated:

[FORM OF REVERSE SIDE OF NOTE]

2.900% Senior Notes due 2030

Parker-Hannifin Corporation, a corporation duly organized and existing under the laws of Ohio (herein called the “Company,” which term includes any successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay interest on the principal amount of this Note annually on March 1 of each year, commencing March 1, 2026 at the rate per annum shown above. If an Interest Payment Date or the Maturity Date falls on a day that is not a Business Day, the related payment of interest or principal, as applicable, will be made on the next Business Day as if it were made on the date the payment was due, and no interest will accrue on the amount so payable for the period from and after that Interest Payment Date or the Maturity Date, as the case may be, to the date the payment is made.

Interest on the Notes shall be computed on an annual basis (ACTUAL/ACTUAL (ICMA)). The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Note (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which shall be the Business Day immediately preceding the Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Note (or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Notes not less than 10 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Notes may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture.

Payment of the principal of and any such interest on this Note will be made to Euroclear, Clearstream, or such nominees of such Common Safekeeper, as the case may be, as Holder hereof. The Company shall maintain a Paying Agent authorized by the Company to pay the principal of and any such interest on this Note.

This Note is one of a duly authorized issue of securities of the Company (herein called the “Notes”), issued and to be issued in one or more series under an Indenture, dated as of September 5, 2023 (the “Base Indenture”), between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”), as supplemented by the officer’s certificate, dated February 20, 2025 of Todd M. Leombruno, Executive Vice President and Chief Financial Officer of the Company (the “Officer’s Certificate”) (the Base Indenture as supplemented by the Officers’ Certificate is collectively referred to herein as the “Indenture,” which term shall have the meaning assigned to it in such instrument), between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), and reference is hereby made to the Indenture for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee and the Holders of the Notes and of the terms upon which the Notes are, and are to be, authenticated and delivered. This Note is one of the series designated on the face hereof.

Principal, Interest and Maturity

Payment will be made upon presentation of the Notes at the office of the Paying Agent, currently at 125 Old Broad Street, Fifth Floor, London, EC2N 1AR, United Kingdom; provided, however, that payment of interest may be made at the Company’s option by check mailed to the registered holder on the applicable record date at such address as shall appear in the security register or by wire transfer of immediately available funds to an account specified in writing by such holder to the Company, the Paying Agent and the trustee prior to the relevant record date. So long as the Notes are in book-entry form registered in the name of the nominee of the Common Safekeeper and held by the Common Safekeeper, the Company will make payments of principal and interest to the Common Safekeeper whose nominee is the registered holder of the Global Notes.

Interest payable on any Interest Payment Date for the Notes, any redemption date for the Notes or the maturity date for the Notes will be the amount of interest accrued from, and including, the preceding Interest Payment Date for the Notes in respect of which interest has been paid or duly provided for (or from and including the original issue date, if no interest has been paid or duly provided for with respect to the Notes) to, but excluding,

such Interest Payment Date, redemption date or maturity date, as the case may be. This payment convention is referred to as ACTUAL/ACTUAL (ICMA) as defined in the rulebook of the International Capital Markets Association. If any Interest Payment Date, redemption date or maturity date falls on a day that is not a Business Day, the payment otherwise required to be made on such date will be made on the next succeeding Business Day, and the Company will not be liable for any additional interest as a result of the delay in payment. If a redemption date or maturity date falls on a day that is not a Business Day, the related payment of principal and interest will be made on the next succeeding Business Day, and no interest will accrue on the amounts so payable for the period from and after such date to the next succeeding Business Day.

Issuance in Euro

Initial holders will be required to pay for the Notes in euro, and principal and interest payments in respect of the Notes (including payments made upon any redemption of such Notes) will be payable in euro. The Company has initially appointed as paying agent U.S. Bank Europe DAC, with its registered office at Block F1, Cherrywood Business Park, Cherrywood, Dublin 18, Ireland D18 W2X7, acting through its UK branch from its offices at 125 Old Broad Street, Fifth Floor, London, EC2N 1AR, United Kingdom, under the trade name U.S. Bank Global Corporate Trust.

If euro is unavailable to the Company due to the imposition of exchange controls or other circumstances beyond the Company’s control or if euro is no longer being used by the then member states of the European Monetary Union that have adopted euro as their currency or for the settlement of transactions by public institutions of or within the international banking community, then all payments in respect of the Notes will be made in U.S. dollars until euro is again available to the Company or so used. The amount payable on any date in euro will be converted into U.S. dollars at the rate mandated by the U.S. Federal Reserve Board as of the close of business on the second business day prior to the relevant payment date or, if the U.S. Federal Reserve Board has not mandated a rate of conversion, on the basis of the most recently available market exchange rate for euro. Any payment in respect of the Notes so made in U.S. dollars will not constitute an event of default under the Notes or the Indenture. Neither the trustee nor the Paying Agent shall be responsible for obtaining exchange rates, effecting conversions or otherwise handling redenominations.

Optional Redemption

Prior to February 1, 2030 (one month prior to their maturity date) (the “Par Call Date”), the Company may redeem the Notes at its option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

plus, in each case, accrued and unpaid interest thereon to the redemption date.

On or after the Par Call Date for the Notes, the Company may redeem the Notes, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest thereon to the redemption date.

For the purposes of the optional redemption provisions of the Notes, the following additional terms will be applicable:

“Comparable Government Bond” means, in relation to any Comparable Government Bond Rate calculation, at the discretion of an independent investment bank selected by the Company, a German government bond whose maturity is closest to the Par Call Date, or if such independent investment bank in its discretion determines that such similar bond is not in issue, such other German government bond as such independent investment bank may, with the advice of three brokers of, and/or market makers in, German government bonds selected by such independent investment bank, determine to be appropriate for determining the Comparable Government Bond Rate.

“Comparable Government Bond Rate” means the price, expressed as a percentage (rounded to three decimal places, 0.0005 being rounded upwards), at which the gross redemption yield on the Notes, if they were to be purchased at such price on the third Business Day prior to the date fixed for redemption, would be equal to the gross redemption yield on such Business Day of the applicable Comparable Government Bond on the basis of the middle market price of such Comparable Government Bond prevailing at 11:00 a.m. (London time) on such Business Day as determined by an independent investment bank selected by the Company.

The Company’s actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error. The trustee shall not be responsible for calculating the redemption price or determining the Comparable Government Bond Rate.

Notice of any redemption will be mailed or electronically delivered (or otherwise transmitted in accordance with the depositary’s procedures) at least 10 days but not more than 60 days before the redemption date to each holder of Notes to be redeemed. Any redemption or notice described above may, at the Company’s discretion, be subject to the satisfaction or waiver of one or more conditions precedent. In addition, if such redemption is subject to satisfaction or waiver of one or more conditions precedent, the notice of such redemption shall state that, in the Company’s discretion, the redemption date may be delayed until such time as any or all such conditions shall be satisfied or waived, or such notice may be rescinded and the redemption terminated in the event that any or all such conditions shall not have been satisfied or waived by the redemption date, or by the redemption date so delayed. The Company shall notify holders of any such rescission as soon as practicable after the Company determines that such conditions precedent will not be able to be satisfied or the Company is not able or willing to waive such conditions precedent.

In the case of a partial redemption, selection of the Notes for redemption will be made pursuant to the applicable depositary’s procedures. No Notes of a principal amount of €100,000 or less will be redeemed in part. If any note is to be redeemed in part only, the notice of redemption that relates to the note will state the portion of the principal amount of the note to be redeemed. A new note in a principal amount equal to the unredeemed portion of the note will be issued in the name of the holder of the note upon surrender for cancellation of the original note. For so long as the Notes are held by Euroclear, Clearstream or another depositary, the redemption of the Notes shall be done in accordance with the policies and procedures of the depositary.

Unless the Company defaults in payment of the redemption price, on and after the redemption date interest will cease to accrue on the Notes or portions thereof called for redemption.

For the avoidance of doubt, neither the Trustee nor any Paying Agent shall be responsible for performing any calculations or selections in connection with any optional redemption.

Payment of Additional Amounts

All payments of principal and interest in respect of the Notes will be made free and clear of, and without deduction or withholding for or on account of, any present or future tax, assessment or other governmental charge required to be deducted or withheld by the United States or a taxing authority in the United States, unless such withholding or deduction is required by law. The Company will, subject to the exceptions and limitations set forth below, pay as additional interest on the Notes such additional amounts as are necessary in order that the net payment by The Company or the Paying Agent of the principal of and interest on the Notes to a holder who is not a United States person (as defined below), after withholding or deduction for any present or future tax, assessment or other governmental charge imposed by the United States or a taxing authority in the United States will not be less than the amount provided in the Notes to be then due and payable; provided, however, that the foregoing obligation to pay additional amounts shall not apply:

Except as specifically provided under this heading “Payment of Additional Amounts,” the Company will not be required to pay additional amounts in respect of any tax, assessment or other governmental charge.

As used under this heading “Payment of Additional Amounts” and under the heading “Redemption for Tax Reasons,” the term “United States” means the United States of America (including the states and the District of Columbia and any political subdivision thereof), and the term “United States person” means (i) any individual who is a citizen or resident of the United States for U.S. federal income tax purposes, (ii) a corporation, partnership or other entity created or organized in or under the laws of the United States (other than a partnership that is not treated as a United States person for U.S. federal income tax purposes), (iii) any estate the income of which is subject to United States federal income taxation regardless of its source, or (iv) any trust if a U.S. court can exercise primary supervision over the administration of the trust and one or more United States persons can control all substantial trust decisions, or if a valid election is in place to treat the trust as a United States person. Any reference in the terms of the Notes to any amounts in respect of the Notes shall be deemed also to refer to any additional amounts which may be payable under this provision.

Redemption for Tax Reasons

If, as a result of any change in, or amendment to, the laws (or any regulations or rulings promulgated under the laws) of the United States (or any taxing authority in the United States), or any change in, or amendment to, an official position regarding the application or interpretation of such laws, regulations or rulings, which change or amendment is announced or becomes effective on or after February 6, 2025, the Company becomes or, based upon a written opinion of independent counsel selected by the Company, will become obligated to pay additional amounts as described herein under the heading “Payment of Additional Amounts” with respect to the Notes, then the Company may at any time at its option redeem, in whole, but not in part, the Notes on not less than 10 nor more than 60 days prior notice, at a redemption price equal to 100% of their principal amount, together with accrued and unpaid interest on the Notes to, but not including, the date fixed for redemption.

Repurchase Upon a Change of Control

If a Change of Control Triggering Event (as defined below) occurs with respect to the Notes, unless the Company has exercised its option to redeem the Notes as described above, the Company will be required to make an offer (a “Change of Control Offer”) to each holder of the Notes to repurchase all or any part (equal to €100,000 or an integral multiple of €1,000 in excess thereof) of that holder’s Notes on the terms set forth in such Notes. In a Change of Control Offer, the Company will be required to offer payment in cash equal to 101% of the aggregate principal amount of Notes repurchased, plus accrued and unpaid interest, if any, on the Notes repurchased to the date of repurchase (a “Change of Control Payment”).

Within 30 days following any such Change of Control Triggering Event or, at the Company’s option, prior to any Change of Control (as defined below), but after public announcement of the transaction that constitutes or may constitute the Change of Control, a notice will be mailed or electronically delivered, or with respect to Notes held in global form, to the extent permitted or required by applicable procedures or regulations of Euroclear and Clearstream, sent electronically to holders of the Notes, with a copy to the Trustee under the Indenture and the Paying Agent that such Notes are being issued under, describing the transaction that constitutes or may constitute

the Change of Control Triggering Event and offering to repurchase such Notes on the date specified in the notice, which date will be no earlier than 10 days and (unless delivered in advance of the occurrence of such Change of Control Triggering Event) no later than 60 days from the date such notice is mailed or sent (a “Change of Control Payment Date”). The notice will, if mailed or sent prior to the date of consummation of the Change of Control, state that the Change of Control Offer is conditioned on the Change of Control Triggering Event occurring.

On each Change of Control Payment Date, the Company will, to the extent lawful:

The Company will not be required to make a Change of Control Offer upon the occurrence of a Change of Control Triggering Event if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for a Change of Control Offer made by the Company, and the third party repurchases all Notes properly tendered and not withdrawn under its offer.

The Company will comply with the requirements of Rule 14e-1 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the Notes as a result of a Change of Control Triggering Event. To the extent that the provisions of any such securities laws or regulations conflict with the Change of Control Offer provisions of the Notes, the Company will comply with those securities laws and regulations and will not be deemed to have breached its obligations under the Change of Control Offer provisions of the Notes by virtue of any such conflict.

If holders of not less than 90% in aggregate principal amount of the outstanding Notes validly tender and do not withdraw such Notes in a Change of Control Offer and the Company, or any third party making a Change of Control Offer in lieu of the Company, as described above, purchases all of the Notes validly tendered and not withdrawn by such holders, the Company will have the right, upon not less than 10 nor more than 60 days’ prior notice, given not more than 30 days following such purchase pursuant to the Change of Control Offer described above, to redeem all Notes that remain outstanding following such purchase at a redemption price in cash equal to the applicable Change of Control Payment.

Neither the Trustee nor any Paying Agent shall be responsible for determining whether any Change of Control Triggering Event has occurred and whether any Change of Control Offer with respect to the Notes is required. Neither the Trustee nor any Paying Agent shall be responsible for monitoring the Company’s rating status, making any request upon any Rating Agency, or determining whether any rating event with respect to the Notes has occurred.

For purposes of the Change of Control Offer provisions of the Notes, the following terms will be applicable:

“Change of Control” means the occurrence of any of the following: (1) the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or more related transactions, of all or substantially all of the Company’s assets and the assets of the Company’s subsidiaries, taken as a whole, to any person, other than the Company or one of its subsidiaries; (2) the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any person becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more than 50% of the Company’s outstanding Voting Stock (as defined below), measured by voting power rather than number of shares; (3) the Company consolidates with, or merges with or into, any person, or any person

consolidates with, or merges with or into, the Company, in any such event pursuant to a transaction in which any of the Company’s outstanding Voting Stock or the Voting Stock of such other person is converted into or exchanged for cash, securities or other property, other than any such transaction where the shares of the Company’s Voting Stock outstanding immediately prior to such transaction constitute, or are converted into or exchanged for, a majority of the Voting Stock of the surviving person or any direct or indirect parent company of the surviving person, measured by voting power rather than number of shares, immediately after giving effect to such transaction; (4) the first day on which a majority of the members of the Board of Directors are not Continuing Directors; or (5) the adoption of a plan relating to the Company’s liquidation or dissolution. The term “person,” as used in this definition, has the meaning given thereto in Section 13(d)(3) of the Exchange Act.

Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control if (1) the Company becomes a direct or indirect wholly owned subsidiary of a holding company and (2)(A) the direct or indirect holders of the Voting Stock of such holding company immediately following that transaction are substantially the same as the holders of the Company’s Voting Stock immediately prior to that transaction or (B) immediately following that transaction no person (other than a holding company satisfying the requirements of this sentence) is the beneficial owner, directly or indirectly, of more than 50% of the Voting Stock of such holding company.

“Change of Control Triggering Event” means the occurrence of both a Change of Control and a Rating Event.

“Continuing Directors” means, as of any date of determination, any member of the Board of Directors who (1) was a member of such Board of Directors on the date the Notes were issued or (2) was nominated for election, elected or appointed to such Board of Directors with the approval of a majority of the directors who were members of such Board of Directors at the time of such nomination, election or appointment (either by a specific vote or by approval of the Company’s proxy statement in which such member was named as a nominee for election as a director, without objection to such nomination).

“Fitch” means Fitch Ratings Inc., and its successors.

“Investment Grade Rating” means a rating equal to or higher than BBB- (or the equivalent) by Fitch, Baa3 (or the equivalent) by Moody’s, and BBB- (or the equivalent) by S&P, and the equivalent investment grade credit rating from any replacement rating agency or Rating Agencies selected by the Company.

“Moody’s” means Moody’s Investors Service, Inc., and its successors.

“Rating Agencies” means (1) each of Fitch, Moody’s and S&P; and (2) if any of Fitch, Moody’s or S&P ceases to rate the Notes or fails to make a rating of the Notes publicly available for reasons outside of the Company’s control, a “nationally recognized statistical rating organization” within the meaning of Section 3(a)(62) of the Exchange Act selected by the Company (as certified by a resolution of the Board of Directors) as a replacement agency for Fitch, Moody’s or S&P, or all of them, as the case may be, with respect to the Notes.

“Rating Event” means the rating on the Notes is lowered by at least two of the three Rating Agencies and the Notes are rated below an Investment Grade Rating by at least two of the three Rating Agencies on any day within the 60-day period (which 60-day period will be extended so long as the rating of the Notes is under publicly announced consideration for a possible downgrade by any of the Rating Agencies) after the earlier of (1) the occurrence of a Change of Control and (2) public notice of the occurrence of a Change of Control or the Company’s intention to effect a Change of Control.

“S&P” means S&P Global Ratings, a division of S&P Global Inc., and its successors.

“Voting Stock” means, with respect to any specified “person” (as that term is used in Section 13(d)(3) of the Exchange Act) as of any date, the capital stock of such person that is at the time entitled to vote generally in the election of the board of directors of such person.

Defeasance and Discharge

The Indenture contains provisions for defeasance at any time of the entire indebtedness of this Note or certain restrictive covenants and Events of Default with respect to this Note, in each case upon compliance with certain conditions set forth in the Indenture.

Events of Default

If an Event of Default with respect to the Notes shall occur and be continuing, the principal of the Notes may be declared due and payable in the manner and with the effect provided in the Indenture.

Modification and Waiver

The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the Holders of the Notes of each series to be affected under the Indenture at any time by the Company and the Trustee with the consent of the Holders of a majority in principal amount of the Notes at the time Outstanding of each series to be affected. The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Notes of each series at the time Outstanding, on behalf of the Holders of all Notes, to waive compliance by the Company with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Note shall be conclusive and binding upon such Holder and upon all future Holders of this Note and of any Note issued upon the registration of transfer hereof or in exchange herefor or in lieu hereof, whether or not notation of such consent or waiver is made upon this Note.

Remedies

As provided in and subject to the provisions of the Indenture, the Holder of this Note shall not have the right to institute any proceeding with respect to the Indenture or for the appointment of a receiver or trustee or for any other remedy thereunder, unless such Holder shall have previously given the Trustee written notice of a continuing Event of Default with respect to the Notes of this series, the Holders of not less than 25% in principal amount of the Notes of this series at the time Outstanding shall have made written request to the Trustee to institute proceedings in respect of such Event of Default as Trustee and offered the Trustee reasonable indemnity, and the Trustee shall not have received from the Holders of a majority in principal amount of Notes of this series at the time Outstanding a direction inconsistent with such request, and shall have failed to institute any such proceeding, for 60 days after receipt of such notice, request and offer of indemnity. The foregoing shall not apply to any suit instituted by the Holder of this Note for the enforcement of any payment of principal hereof or interest hereon on or after the respective due dates expressed herein.

No reference herein to the Indenture and no provision of this Note or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of and interest on this Note at the times, place and rate, and in the coin or currency, herein prescribed.

Transfer and Exchange

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Note is registrable in the Security Register, upon surrender of this Note for registration of transfer at the office or agency of the Company in any place where the principal of and interest on this Note are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Notes of this series, and of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.

The Notes are issuable only in registered form without coupons in denominations of €100,000 and any integral multiple of €1,000 in excess thereof. As provided in the Indenture and subject to certain limitations therein set forth, Notes of this series are exchangeable for a like aggregate principal amount of Notes of this series and of like tenor, of a different authorized denomination, as requested by the Holder surrendering the same. No service charge shall be made for any such registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

Prior to due presentment of this Note for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person in whose name this Note is registered as the owner hereof for all purposes, whether or not this Note be overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to the contrary.

All terms used in this Note which are defined in the Indenture shall have the meanings assigned to them in the Indenture. Unless the certificate of authentication hereon has been executed by the Trustee by manual or electronic signature, this Note shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

Governing Law

The Indenture and the Notes shall be governed by and construed in accordance with the law of the State of New York.

Defined Terms

All terms used in this Note which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

ASSIGNMENT

FOR VALUE RECEIVED, the undersigned assigns and transfers this Note to:

(Insert assignee’s social security or tax identification number)

(Insert address and zip code of assignee)

and irrevocably appoints

agent to transfer this Note on the books of the Company. The agent may substitute another to act for him or her.

Date:

(Sign exactly as your name appears on the other side of this Note)

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Security Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Security Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

SCHEDULE OF INCREASES OR DECREASES IN NOTE

The initial principal amount of this Note is €700,000,000. The following increases or decreases in the principal amount of this Note have been made:

Exhibit 5.1

2727 NORTH HARWOOD STREET • DALLAS, TEXAS 75201.1515

TELEPHONE: +1.214.220.3939 • JONESDAY.COM

February 20, 2025 

Parker-Hannifin Corporation

6035 Parkland Boulevard

Cleveland, Ohio 44124-4141

Ladies and Gentlemen:

We are acting as counsel for Parker-Hannifin Corporation, an Ohio corporation (the “Company”), in connection with the issuance and sale of €700,000,000 aggregate principal amount of the Company’s 2.900% Senior Notes due 2030 (the “Notes”), pursuant to the Underwriting Agreement, dated as of February 6, 2025 (the “Underwriting Agreement”), among the Company and Citigroup Global Markets Limited, HSBC Bank plc and Morgan Stanley & Co. International plc, acting as representatives (in such capacity, the “Representatives”) of the several underwriters named therein. The Notes are being issued under an Indenture, dated as of September 5, 2023 (the “Indenture”), between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”), and an Officer’s Certificate, dated February 20, 2025, setting forth the terms of the Notes.

In connection with the opinion expressed herein, we have examined such documents, records and matters of law as we have deemed relevant or necessary for purposes of this opinion. Based on the foregoing, and subject to the further limitations, qualifications and assumptions set forth herein, we are of the opinion that the Notes constitute valid and binding obligations of the Company.

The opinion set forth above is subject to the following limitations, qualifications and assumptions:

For purposes of the opinion expressed herein, we have assumed that (i) the Trustee has authorized, executed and delivered the Indenture, (ii) the Notes have been duly authenticated by the Trustee in accordance with the terms of the Indenture and (iii) the Indenture is the valid, binding and enforceable obligation of the Trustee.

The opinion expressed herein is limited by (i) bankruptcy, insolvency, reorganization, fraudulent transfer and fraudulent conveyance, voidable preference, moratorium or other similar laws and related regulations and judicial doctrines from time to time in effect relating to or affecting creditors’ rights generally and (ii) general equitable principles and public policy considerations, whether such principles and considerations are considered in a proceeding at law or at equity.

AMSTERDAM • ATLANTA • BEIJING • BOSTON • BRISBANE • BRUSSELS • CHICAGO • CLEVELAND • COLUMBUS • DALLAS

DETROIT • DUBAI • DÜSSELDORF • FRANKFURT • HONG KONG • HOUSTON • IRVINE • LONDON • LOS ANGELES • MADRID

MELBOURNE • MEXICO CITY • MIAMI • MILAN • MINNEAPOLIS • MUNICH • NEW YORK • PARIS • PERTH • PITTSBURGH

SAN DIEGO • SAN FRANCISCO • SÃO PAULO • SHANGHAI • SILICON VALLEY • SINGAPORE • SYDNEY • TAIPEI • TOKYO • WASHINGTON

Parker-Hannifin Corporation

February 20, 2025

Page 2

As to facts material to the opinion and assumptions expressed herein, we have relied upon oral or written statements and representations of officers and other representatives of the Company and others. The opinion expressed herein is limited to the laws of the State of New York and the laws of the State of Ohio, as currently in effect, and we express no opinion as to the effect of the laws of any other jurisdiction.

We hereby consent to the filing of this opinion as Exhibit 5.1 to the Current Report on Form 8-K dated the date hereof filed by the Company and incorporated by reference into the Registration Statement on Form S-3 (File No. 333-274347) (the “Registration Statement”), filed by the Company to effect the registration of the Notes under the Securities Act of 1933 (the “Act”) and to the reference to Jones Day under the caption “Legal Matters” in the prospectus constituting a part of such Registration Statement. In giving such consent, we do not thereby admit that we are included in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Securities and Exchange Commission promulgated thereunder.