Exhibit 3.1

FORM OF

AMENDED AND RESTATED

CERTIFICATE OF INCORPORATION

CACTUS, INC.

Cactus, Inc. (the “Corporation”), a corporation organized and existing under the General Corporation Law of the State of Delaware as set forth in Title 8 of the Delaware Code (the “DGCL”), hereby certifies as follows:

1. The original Certificate of Incorporation of the Corporation (the “Original Certificate of Incorporation”) was filed with the Secretary of State of the State of Delaware on February 17, 2017.

2. This Amended and Restated Certificate of Incorporation (this “Amended and Restated Certificate of Incorporation”), which restates and amends the Original Certificate of Incorporation, has been declared advisable by the board of directors of the Corporation (the “Board”), duly adopted by the stockholders of the Corporation and duly executed and acknowledged by the officers of the Corporation in accordance with Sections 103, 228, 242 and 245 of the DGCL.

3. The Original Certificate of Incorporation is hereby amended and restated in its entirety to read as follows:

FIRST: The name of the Corporation is Cactus, Inc.

SECOND: The address of its registered office in the State of Delaware is The Corporation Trust Center, 1209 Orange Street, Wilmington, Delaware 19801 in New Castle County, Delaware. The name of its registered agent at such address is The Corporation Trust Company.

THIRD: The nature of the business or purposes to be conducted or promoted by the Corporation is to engage in any lawful act or activity for which corporations may be organized under the DGCL as it currently exists or may hereafter be amended.

FOURTH: The total number of shares of stock that the Corporation shall have the authority to issue is shares of stock, classified as (i) shares of preferred stock, par value $0.01 per share (“Preferred Stock”), (ii) shares of Class A common stock, par value $0.01 per share (“Class A Common Stock”), and (iii) shares of Class B common stock, par value $0.01 per share (“Class B Common Stock” and, together with the Class A Common Stock, the “Common Stock”).

1. Provisions Relating to Preferred Stock.

(a) Preferred Stock may be issued from time to time in one or more classes or series, the shares of each class or series to have such designations and powers, preferences and rights, and qualifications, limitations and restrictions thereof, as are stated and expressed herein and in the resolution or resolutions providing for the issue of such class or series adopted by the Board as hereafter prescribed (a “Preferred Stock Designation”).

(b) Subject to any limitations prescribed by law, and the rights of any series of the Preferred Stock then outstanding, if any, authority is hereby expressly granted to and vested in the Board to authorize the issuance of Preferred Stock from time to time in one or more classes or series, and with respect to each series of Preferred Stock, to fix and state by the resolution or resolutions from time to time adopted by the Board providing for the issuance thereof the designation and the powers, preferences, privileges and rights, qualifications, limitations and restrictions relating to each series of Preferred Stock, including, but not limited to, the following:

(i) whether or not the class or series is to have voting rights, full, special or limited, or is to be without voting rights, and whether or not such series is to be entitled to vote as a separate class or series either alone or together with the holders of one or more other classes or series of stock;

(ii) the number of shares to constitute the class or series and the designations thereof;

(iii) the powers, preferences, privileges and relative, participating, optional or other special rights, if any, and the qualifications, limitations or restrictions thereof, if any, with respect to any series;

(iv) whether or not the shares of any class or series shall be redeemable at the option of the Corporation or the holders thereof or upon the happening of any specified event, and, if redeemable, the redemption price or prices (which may be payable or issuable in the form of cash, notes, securities or other property), and the time or times at which, and the terms and conditions upon which, such shares shall be redeemable and the manner of redemption;

(v) whether or not the shares of a class or series shall be subject to the operation of retirement or sinking funds to be applied to the purchase or redemption of such shares for retirement, and, if such retirement or sinking fund or funds are to be established, the annual amount thereof, and the terms and provisions relative to the operation thereof;

(vi) the dividend rate, whether dividends are payable or issuable in cash, stock of the Corporation or other property, the conditions upon which and the times when such dividends are payable or issuable, the preference to or the relation to the payment or issuable of dividends payable or issuable on any other class or classes or series of stock, whether or not such dividends shall be cumulative or noncumulative, and if cumulative, the date or dates from which such dividends shall accumulate, and whether such dividends shall be compounded and if so the rate of such compounding;

(vii) the preferences, if any, and the amounts thereof which the holders of any class or series thereof shall be entitled to receive upon the voluntary or involuntary liquidation, dissolution or winding up of, or upon any distribution of the assets of, the Corporation;

(viii) whether or not the shares of any series, at the option of the Corporation or the holder thereof or upon the happening of any specified event, shall be convertible into or exchangeable for, the shares of any other class or classes or of any other series of the same or any other class or classes, or series of stock, securities or other property of the Corporation and the conversion price or prices or ratio or ratios or the rate or rates at which such exchange may be made, with such adjustments, if any, as shall be stated and expressed or provided for in such resolution or resolutions; and

(ix) such other powers, privileges, preferences, rights, qualifications, limitations and restrictions with respect to any series as may to the Board seem advisable.

(c) The shares of each series of Preferred Stock may vary from the shares of any other class or series thereof in any or all of the foregoing respects.

2. Provisions Relating to Common Stock.

(a) Except as may otherwise be provided in this Amended and Restated Certificate of Incorporation (including for the avoidance of doubt the terms of Section 2(d)), each share of Common Stock shall have identical rights and privileges in every respect. Common Stock shall be subject to the express terms of Preferred Stock and any series thereof. Except as may otherwise be provided in this Amended and Restated Certificate of Incorporation, in a Preferred Stock Designation or by applicable law, the holders of shares of Common Stock shall be entitled to one vote for each such share on all matters upon which the stockholders are entitled to vote, the holders of shares of Common Stock shall have the exclusive right to vote for the election of directors and for all other matters upon which the stockholders are entitled to vote, and the holders of Preferred Stock shall not be entitled to vote at or receive notice of any meeting of stockholders, other than as provided in the applicable Preferred Stock Designation. Each holder of Common Stock shall be entitled to notice of any stockholders’ meeting in accordance with the Bylaws (as in effect at the time in question) and applicable law on all matters put to a vote of the stockholders of the Corporation. Except as otherwise required in this Amended and Restated Certificate of Incorporation (including any Preferred Stock Designation) or by applicable law, the holders of Common Stock shall vote together as a single class on all matters (or, if any holders of Preferred Stock are entitled to vote together with the holders of Common Stock, the holders of Common Stock and the Preferred Stock shall vote together as a single class).

(b) Notwithstanding the foregoing, except as otherwise required by applicable law, holders of Common Stock, as such, shall not be entitled to vote on any amendment to this Amended and Restated Certificate of Incorporation (including any Preferred Stock Designation) that relates solely to the terms of one or more outstanding series of Preferred Stock if the holders of such affected series are entitled, either separately or together with the holders of one or more

other such series, to vote thereon pursuant to this Amended and Restated Certificate of Incorporation (including any Preferred Stock Designation) or pursuant to the DGCL.

(c) Subject to the prior rights and preferences, if any, applicable to shares of Preferred Stock or any series thereof, the holders of shares of Class A Common Stock shall be entitled to receive ratably in proportion to the number of shares of Class A Common Stock held by them such dividends and distributions (payable or issuable in cash, stock or otherwise), if any, as may be declared thereon by the Board at any time and from time to time out of any funds of the Corporation legally available therefor. Dividends and other distributions shall not be declared or paid on the Class B Common Stock unless (i) the dividend consists of shares of Class B Common Stock or of rights, options, warrants or other securities convertible or exercisable into or exchangeable for shares of Class B Common Stock paid proportionally with respect to each outstanding share of Class B Common Stock and (ii) a dividend consisting of shares of Class A Common Stock or of rights, options, warrants or other securities convertible or exercisable into or exchangeable for shares of Class A Common Stock on equivalent terms is simultaneously paid to the holders of Class A Common Stock. If dividends are declared on the Class A Common Stock or the Class B Common Stock that are payable or issuable in shares of Common Stock, or securities convertible into, or exercisable or exchangeable for Common Stock, the dividends payable or issuable to the holders of Class A Common Stock shall be paid only in shares of Class A Common Stock (or securities convertible into, or exercisable or exchangeable for Class A Common Stock), the dividends payable to the holders of Class B Common Stock shall be paid only in shares of Class B Common Stock (or securities convertible into, or exercisable or exchangeable for Class B Common Stock), and such dividends shall be paid in the same number of shares (or fraction thereof) on a per share basis of the Class A Common Stock and Class B Common Stock, respectively (or securities convertible into, or exercisable or exchangeable for the same number of shares (or fraction thereof) on a per share basis of the Class A Common Stock and Class B Common Stock, respectively). In no event shall the shares of either Class A Common Stock or Class B Common Stock be split, divided, or combined unless the outstanding shares of the other class shall be proportionately split, divided or combined.

(d) In the event of any voluntary or involuntary liquidation, dissolution or winding-up of the Corporation, after distribution in full of the preferential amounts, if any, to be distributed to the holders of shares of Preferred Stock or any series thereof as provided in the applicable Preferred Stock Designation, the holders of shares of Class A Common Stock shall be entitled to receive all of the remaining assets of the Corporation available for distribution to its stockholders, ratably in proportion to the number of shares of Common Stock held by them. The holders of shares of Class B Common Stock, as such, shall not be entitled to receive any assets of the Corporation in the event of any voluntary or involuntary liquidation, dissolution or winding up of the affairs of the Corporation. A dissolution, liquidation or winding-up of the Corporation, as such terms are used in this paragraph (d), shall not be deemed to be occasioned by or to include any consolidation or merger of the Corporation with or into any other corporation or corporations or other entity or a sale, lease, exchange or conveyance of all or a part of the assets of the Corporation.

(e) Shares of Class B Common Stock shall be redeemable for shares of Class A Common Stock on the terms and subject to the conditions set forth in the First Amended and Restated Limited Liability Agreement of Cactus Wellhead, LLC dated as of , 2018, as the

same may be amended from time to time in accordance with its terms (the “LLC Agreement”). The Corporation will at all times reserve and keep available out of its authorized but unissued shares of Class A Common Stock, solely for the purpose of issuance upon redemption of the outstanding shares of Class B Common Stock for Class A Common Stock pursuant to the LLC Agreement, such number of shares of Class A Common Stock that shall be issuable upon any such redemption pursuant to the LLC Agreement; provided that nothing contained herein shall be construed to preclude the Corporation from satisfying its obligations in respect of any such redemption of shares of Class B Common Stock pursuant to the LLC Agreement by delivering to the holder of shares of Class B Common Stock upon such redemption, cash in lieu of shares of Class A Common Stock in the amount permitted by and provided in the LLC Agreement or shares of Class A Common Stock which are held in the treasury of the Corporation. All shares of Class A Common Stock that shall be issued upon any such redemption will, upon issuance in accordance with the LLC Agreement, be validly issued, fully paid and non-assessable. All shares of Class B Common Stock redeemed shall be cancelled.

(f) The number of authorized shares of Common Stock or Preferred Stock may be increased or decreased (but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of a majority in voting power of the outstanding shares of stock of the Corporation entitled to vote thereon irrespective of the provisions of Section 242(b)(2) of the DGCL (or any successor provision thereto), and no vote of the holders of either Common Stock or Preferred Stock voting separately as a class shall be required therefor.

(g) No stockholder shall, by reason of the holding of shares of any class or series of capital stock of the Corporation, have any preemptive or preferential right to acquire or subscribe for any shares or securities of any class or series, whether now or hereafter authorized, which may at any time be issued, sold or offered for sale by the Corporation, unless specifically provided for in the terms of a series of Preferred Stock.

FIFTH: The business and affairs of the Corporation shall be managed by or under the direction of the Board. In addition to the powers and authority expressly conferred upon them by statute or by this Amended and Restated Certificate of Incorporation or the Bylaws (as they may be amended and restated from time to time, the “Bylaws”), the directors are hereby empowered to exercise all such powers and do all such acts and things as may be exercised or done by the Corporation. The directors, other than those who may be elected by the holders of any series of Preferred Stock specified in the related Preferred Stock Designation, shall be divided, with respect to the time for which they severally hold office, into three classes, as nearly equal in number as is reasonably possible, with the initial term of office of the first class to expire at the 2018 annual meeting (the “Class I Directors”), the initial term of office of the second class to expire at the 2019 annual meeting (the “Class II Directors”), and the initial term of office of the third class to expire at the 2020 annual meeting (the “Class III Directors”), with each director to hold office until his successor shall have been duly elected and qualified, subject, however, to such director’s earlier death, disability, resignation, disqualification or removal. At each annual meeting of stockholders, directors elected to succeed those directors whose terms then expire shall be elected for a term of office to expire at the third succeeding annual meeting of stockholders after their election, with each director to hold office until his successor shall have been duly elected and qualified, subject, however, to such director’s earlier death, disability, resignation, disqualification or removal. The Board is authorized to assign members of the

Board already in office to Class I, Class II or Class III at the time such classification becomes effective. Subject to applicable law, the rights of the holders of any series of Preferred Stock then outstanding and the then-applicable terms of the Stockholders’ Agreement, among the Corporation and certain of its stockholders, expected to be dated on or about , 2018 (the “Stockholders’ Agreement”), any newly created directorship that results from an increase in the number of directors or any vacancy on the Board that results from the death, disability, resignation, disqualification or removal of any director or from any other cause shall be filled solely by the affirmative vote of a majority of the total number of directors then in office, even if less than a quorum, or by a sole remaining director and shall not be filled by the stockholders. Any director elected to fill a vacancy not resulting from an increase in the number of directors shall hold office for the remaining term of his predecessor. No decrease in the number of authorized directors constituting the Board shall shorten the term of any incumbent director.

Subject to the rights of the holders of shares of any series of Preferred Stock, if any, to elect additional directors pursuant to this Amended and Restated Certificate of Incorporation (including any Preferred Stock Designation thereunder) and the then-applicable terms of the Stockholders’ Agreement, any director may be removed only for cause, upon the affirmative vote of the holders of at least 662/3% of the outstanding shares of stock of the Corporation entitled to vote generally for the election of directors, acting at a meeting of the stockholders in accordance with the DGCL, this Amended and Restated Certificate of Incorporation and the Bylaws. Except as applicable law otherwise provides, cause for the removal of a director shall be deemed to exist only if the director whose removal is proposed: (i) has been convicted of a felony by a court of competent jurisdiction and that conviction is no longer subject to direct appeal; (ii) has been found to have been grossly negligent in the performance of his duties to the Corporation in any matter of substantial importance to the Corporation by the affirmative vote of at least 80% of the directors then in office or a court of competent jurisdiction; or (iii) has been adjudicated by a court of competent jurisdiction to be mentally incompetent, which mental incompetency directly affects his ability to serve as a director of the Corporation.

Subject to the rights of the holders of any series of Preferred Stock to elect directors under specified circumstances, if any, the number of directors shall be fixed from time to time exclusively pursuant to a resolution adopted by the affirmative vote of a majority of the Board. Unless and except to the extent that the Bylaws so provide, the election of directors need not be by written ballot. There shall be no cumulative voting in the election of directors.

SIXTH: Subject to the rights of holders of any series of Preferred Stock with respect to such series of Preferred Stock, any action required or permitted to be taken by the stockholders of the Corporation must be taken at a duly held annual or special meeting of stockholders and may not be taken by any consent in writing of such stockholders.

SEVENTH: Except as otherwise required by law and subject to the rights of the holders of any series of Preferred Stock, special meetings of stockholders of the Corporation may be called only by the Chief Executive Officer, the Chairman of the Board or the Board pursuant to a resolution adopted by the affirmative vote of a majority of the total number of directors that the Corporation would have if there were no vacancies. Subject to the rights of holders of any series of Preferred Stock, the stockholders of the Corporation shall not have the power to call a special meeting of stockholders of the Corporation.

EIGHTH: In furtherance of, and not in limitation of, the powers conferred by the laws of the State of Delaware, the Board is expressly authorized to adopt, amend or repeal the Bylaws without any action on the part of the stockholders of the Corporation; provided that any bylaw adopted or amended by the Board, and any powers thereby conferred, may be amended, altered or repealed by the stockholders of the Corporation by the vote of holders of not less than 662/3% in voting power of the then-outstanding shares of stock entitled to vote thereon, voting together as a single class. No Bylaws hereafter made or adopted, nor any repeal of or amendment thereto, shall invalidate any prior act of the Board that was valid at the time it was taken.

NINTH: No director of the Corporation shall be liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a director, except to the extent such exemption from liability or limitation thereof is not permitted under the DGCL as it now exists. In addition to the circumstances in which a director of the Corporation is not personally liable as set forth in the preceding sentence, a director of the Corporation shall not be liable to the fullest extent permitted by any amendment to the DGCL hereafter enacted that further limits the liability of a director.

Any amendment, repeal or modification of this Article Ninth shall be prospective only and shall not affect any limitation on liability of a director for acts or omissions occurring prior to the date of such amendment, repeal or modification.

TENTH: To the fullest extent permitted by applicable law, the Corporation, on behalf of itself and its subsidiaries, renounces any interest or expectancy of the Corporation and its subsidiaries in, or in being offered an opportunity to participate in, any business opportunities that are from time to time presented to Cadent Energy Partners II, L.P. and its affiliates (the “Sponsor”) or any of their respective affiliates or any of their respective agents, shareholders, members, partners, directors, officers, employees, affiliates or subsidiaries (other than the Corporation and its subsidiaries), including any director or officer of the Corporation who is also an agent, shareholder, member, partner, director, officer, employee, affiliate or subsidiary of the Sponsor (each, a “Business Opportunities Exempt Party”), even if the business opportunity is one that the Corporation or its subsidiaries might reasonably be deemed to have pursued or had the ability or desire to pursue if granted the opportunity to do so, and no Business Opportunities Exempt Party shall have any duty to communicate or offer any such business opportunity to the Corporation or be liable to the Corporation or any of its subsidiaries or any stockholder of the Corporation, including for breach of any fiduciary or other duty, as a director or officer or controlling stockholder or otherwise, and the Corporation shall indemnify each Business Opportunities Exempt Party against any claim that such person is liable to the Corporation or its stockholders for breach of any fiduciary duty, by reason of the fact that such person (i) participates in, pursues or acquires any such business opportunity, (ii) directs any such business opportunity to another person or (iii) fails to present any such business opportunity, or information regarding any such business opportunity, to the Corporation or its subsidiaries, unless, in the case of a person who is a director or officer of the Corporation, such business opportunity is expressly offered to such director or officer in writing solely in his capacity as a director or officer of the Corporation.

To the fullest extent permitted by law, no Business Opportunity Exempt Party shall have any duty to refrain from directly or indirectly (1) engaging in the same or similar business

activities or lines of business in which the Corporation or any of its affiliates now engages or proposes to engage or (2) otherwise competing with the Corporation or any of its affiliates, and, to the fullest extent permitted by law, no Business Opportunity Exempt Party shall be liable to the Corporation or its stockholders or to any affiliate of the Corporation for breach of any fiduciary duty solely by reason of the fact that such Business Opportunity Exempt Party engages in any such activities.

Neither the amendment nor repeal of this Article Tenth, nor the adoption of any provision of this Amended and Restated Certificate of Incorporation or the Bylaws, nor, to the fullest extent permitted by Delaware law, any modification of law, shall eliminate, reduce or otherwise adversely affect any right or protection of any person granted pursuant hereto existing at, or arising out of or related to any event, act or omission that occurred prior to, the time of such amendment, repeal, adoption or modification (regardless of when any proceeding (or part thereof) relating to such event, act or omission arises or is first threatened, commenced or completed).

If any provision or provisions of this Article Tenth shall be held to be invalid, illegal or unenforceable as applied to any circumstance for any reason whatsoever, (a) the validity, legality and enforceability of such provisions in any other circumstance and of the remaining provisions of this Article Tenth (including, without limitation, each portion of any paragraph of this Article Tenth containing any such provision held to be invalid, illegal or unenforceable that is not itself held to be invalid, illegal or unenforceable) shall not in any way be affected or impaired thereby and (b) to the fullest extent possible, the provisions of this Article Tenth (including, without limitation, each such portion of any paragraph of this Article Tenth containing any such provision held to be invalid, illegal or unenforceable) shall be construed so as to permit the Corporation to protect its directors, officers, employees and agents from personal liability in respect of their good faith service to or for the benefit of the Corporation to the fullest extent permitted by applicable law.

This Article Tenth shall not limit any protections or defenses available to, or indemnification or advancement rights of, any director or officer of the Corporation under this Amended and Restated Certificate of Incorporation, the Bylaws or applicable law. Any person or entity purchasing or otherwise acquiring any interest in any securities of the Corporation shall be deemed to have notice of and to have consented to the provisions of this Article Tenth.

ELEVENTH: The Corporation shall not be governed by or subject to the provisions of Section 203 of the DGCL as now in effect or hereafter amended, or any successor statute thereto.

TWELFTH: The Corporation shall have the right, subject to any express provisions or restrictions contained in this Amended and Restated Certificate of Incorporation or Bylaws, from time to time, to amend this Amended and Restated Certificate of Incorporation or any provision hereof in any manner now or hereafter provided by applicable law, and all rights and powers of any kind conferred upon a director or stockholder of the Corporation by this Amended and Restated Certificate of Incorporation or any amendment hereof are subject to such right of the Corporation.

THIRTEENTH: Notwithstanding any other provision of this Amended and Restated Certificate of Incorporation or the Bylaws (and in addition to any other vote that may be required by applicable law, this Amended and Restated Certificate of Incorporation or the Bylaws), the affirmative vote of the holders of at least 662/3% in voting power of the outstanding shares of stock of the Corporation entitled to vote thereon, voting together as a single class, shall be required to amend, alter or repeal any provision of this Amended and Restated Certificate of Incorporation.

Unless the Corporation consents in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware shall, to the fullest extent permitted by applicable law, be the sole and exclusive forum for any stockholder (including a beneficial owner) to bring (i) any derivative action or proceeding brought on behalf of the Corporation, (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer, employee or agent of the Corporation to the Corporation or the Corporation’s stockholders, (iii) any action asserting a claim against the Corporation or any director or officer or other employee of the Corporation arising pursuant to any provision of the DGCL, this Amended and Restated Certificate of Incorporation or the Bylaws, including any action to interpret, apply, enforce or determine the validity of this Amended and Restated Certificate of Incorporation or the Bylaws, or any provision hereof or thereof, or (iv) any action asserting a claim against the Corporation or any director or officer or other agent or employee of the Corporation governed by the internal affairs doctrine, in each such case subject to said Court of Chancery having personal jurisdiction over the indispensable parties named as defendants therein. Any person or entity purchasing or otherwise acquiring any interest in any securities of the Corporation shall be deemed to have notice of and consented to the provisions of this Article Thirteenth.

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IN WITNESS WHEREOF, the undersigned has executed this Amended and Restated Certificate of Incorporation as of this day of , 2018.

	CACTUS, INC.


	By:
	Name:
	Title:

[Signature Page to Amended and Restated Certificate of Incorporation]