Exhibit 3.1

SHILOH INDUSTRIES, INC.

AMENDED AND RESTATED

BY-LAWS

BY-LAWS

Table of Contents

SHILOH INDUSTRIES, INC.

AMENDED AND RESTATED BY-LAWS

ARTICLE 1

MEETINGS OF STOCKHOLDERS

Section 1. Time and Place of Meetings. All meetings of the stockholders for the election of directors or for any other purpose shall be held at such time and place, within or without the State of Delaware, as may be designated by the Board of Directors, or by the Chairman of the Board, the President or the Secretary in the absence of a designation by the Board of Directors, and stated in the notice of the meeting or in a duly executed waiver of notice thereof.

Section 2. Annual Meeting. An annual meeting of the stockholders, commencing with the year 1994, shall be held on the first Monday in March if not a legal holiday, and if a legal holiday, then on the next business day following, at 10:00 a.m., or at such other date and time as shall be designated from time to time by the Board of Directors, at which meeting the stockholders shall elect by a plurality vote the directors to succeed those whose terms expire and shall transact such other business as may properly be brought before the meeting.

Section 3. Special Meetings. Special meetings of the stockholders, for any purpose or purposes, unless otherwise prescribed by law or by Certificate of Incorporation of the Corporation, as amended from time to time (the “Certificate of Incorporation”), may be called only by the Chairman of the Board of Directors, the President, or the Secretary within ten (10) calendar days after receipt of the written request of a majority of the directors of the Corporation. Any such request by a majority of the directors of the Corporation must state the purpose or purposes of the proposed meeting.

Section 4. Notice of Meetings. Written notice of every meeting of the stockholders, stating the place, date and hour of the meeting and, in the case of a special meeting, the purpose or purposes for which the meeting is called, shall be given not less than ten (10) nor more than sixty (60) days before the date of the meeting to each stockholder entitled to vote at such meeting, except as otherwise provided herein or by law. When a meeting is adjourned to another place, date or time, written notice need not be given of the adjourned meeting if the place, date and time thereof are announced at the meeting at which the adjournment is taken; provided, however, that if the adjournment is for more than thirty (30) days, or if after the adjournment a new record date is fixed for the adjourned meeting, written notice of the place, date and time of the adjourned meeting shall be given in conformity herewith. At any adjourned meeting, any business may be transacted which might have been transacted at the original meeting.

Section 5. Quorum. Except as otherwise provided by law, the Certificate of Incorporation or in a Preferred Stock Designation, the holders of a majority of the stock issued and outstanding and entitled to vote thereat, present in person or represented by proxy, shall constitute a quorum at all meetings of the stockholders for the transaction of business. If,

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however, such quorum shall not be present or represented at any meeting of the stockholders, the stockholders entitled to vote thereat, present in person or represented by proxy, shall have power to adjourn the meeting from time to time, without notice other than announcement at the meeting, until a quorum shall be present or represented.

Section 6. Voting. Except as otherwise provided by law, the Certificate of Incorporation or in a Preferred Stock Designation, each stockholder shall be entitled at every meeting of the stockholders to one (I) vote for each share of stock having voting power standing in the name of such stockholder on the books of the Corporation on the record date for the meeting and such votes may be cast either in person or by written proxy. Every proxy must be duly executed and filed with the Secretary of the Corporation. A stockholder may revoke any proxy which is not irrevocable by attending the meeting and voting in person or by filing an instrument in writing revoking the proxy or another duly executed proxy bearing a later date with the Secretary of the Corporation. The vote upon any question brought before a meeting of the stockholders may be by voice vote, unless otherwise required by the Certificate of Incorporation or these By-laws or unless the chairman of the meeting or the holders of a majority of the outstanding shares of all classes of stock entitled to vote thereon present in person or by proxy at such meeting shall so determine. Every vote taken by written ballot shall be counted by one (1) or more inspectors of election appointed by the Board of Directors. When a quorum is present at any meeting, the affirmative vote of the holders of a majority of the stock which has voting power present in person or represented by proxy and which has actually voted shall decide any question properly brought before such meeting, unless the question is one upon which by express provision of law, the Certificate of Incorporation, these By-laws or a Preferred Stock Designation, a different vote is required, in which case such express provision shall govern and control the decision of such question.

ARTICLE II

DIRECTORS

Section 1. Powers. The business and affairs of the Corporation shall be managed by or under the direction of its Board of Directors, which may exercise all such powers of the Corporation and do all such lawful acts and things as are not by law or by the Certificate of Incorporation directed or required to be exercised or done by the stockholders.

Section 2. Number and Term of Office. Subject to the rights, if any, of any series of Preferred Stock to elect additional directors under circumstances specified in a Preferred Stock Designation and to the minimum and maximum number of authorized directors provided in the Certificate of Incorporation, the authorized number of directors shall be fixed by resolution of the Board of Directors or by the stockholders at the annual meeting or a special meeting. The directors, other than those who may be elected by the holders of any series of the Preferred Stock, will be classified with respect to the time for which they severally hold office in accordance with the Certificate of Incorporation. Any decrease in the authorized number of directors shall not be effective until the expiration of the term of the directors then in office, unless, at the time of such decrease, there shall be vacancies on the Board which are being eliminated by such decrease.

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Section 3. Vacancies and New Directorships. Subject to the rights, if any, of the holders of any series of Preferred Stock to elect additional directors under the circumstances specified in a Preferred Stock Designation, vacancies and newly created directorships resulting from any increase in the authorized number of directors which occur between annual meetings of the stockholders may be filled by a majority of the remaining directors then in office, even though less than a quorum, or by a sole remaining director. Any director elected in accordance with the preceding sentence will hold office for the remainder of the full term of the class of directors in which the new directorship was created or the vacancy occurred and until such director’s successor is elected and qualified. No decrease in the number of directors constituting the Board will shorten the term of an incumbent director.

Section 4. Regular Meetings. Regular meetings of the Board of Directors may be held without notice immediately after the annual meeting of the stockholders and at such other time and place as shall from time to time be determined by the Board of Directors.

Section 5. Special Meetings. Special meetings of the Board of Directors may be called by the Chairman of the Board or the President on not less than one (1) day’s written notice to each director by whom such notice is not waived, given either personally or by telegram, telephone, telex, facsimile or similar medium of communication, or by mail, in which case notice must be five (5) days in advance, and shall be called by the President or the Secretary in like manner and on like notice on the written request of any three (3) directors.

Section 6. Quorum. At all meetings of the Board of Directors, a majority of the total number of directors then in office shall constitute a quorum for the transaction of business, and the act of a majority of the directors present at any meeting at which there is a quorum shall be the act of the Board of Directors. If a quorum shall not be present at any meeting of the Board of Directors, the directors present thereat may adjourn the meeting from time to time to another place, time or date, without notice other than announcement at the meeting, until a quorum shall be present.

Section 7. Written Action. Any action required or permitted to be taken at any meeting of the Board of Directors or of any committee thereof may be taken without a meeting if all members of the Board or committee, as the case may be, consent thereto in writing, and the writing or writings are filed with the minutes or proceedings of the Board or Committee.

Section 8. Participation in Meetings by Conference Telephone. Members of the Board of Directors, or any committee designated by the Board of Directors, may participate in a meeting of the Board of Directors, or any such committee, by means of conference telephone or similar communications equipment by means of which all persons participating in the meeting can hear each other, and such participation in a meeting shall constitute presence in person at the meeting.

Section 9. Committees. The Board of Directors may, by resolution passed by a majority of the directors of the Corporation, designate one or more committees, each committee to consist of one (1) or more of the directors of the Corporation and each to have such lawfully delegable powers and duties as the Board of Directors may confer. Each such committee shall serve at the pleasure of the Board of Directors. The Board may designate

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one (1) or more directors as alternate members of any committee, who may replace any absent or disqualified member at any meeting of the committee. Except as otherwise provided by law, any such committee, to the extent provided in the resolution of the Board of Directors, shall have and may exercise all the powers and authority of the Board of Directors in the management of the business and affairs of the Corporation, and may authorize the seal of the Corporation, if any, to be affixed to all papers which may require it. Any committee or committees so designated by the Board shall have such name or names as may be determined from time to time by resolution adopted by the Board of Directors. Unless otherwise prescribed by the Board of Directors, a majority of the members of the committee shall constitute a quorum for the transaction of business, and the act of a majority of the members present at a meeting at which there is a quorum shall be the act of such committee. Each committee shall prescribe its own rules for calling and holding meetings and its method of procedure, subject to any rules prescribed by the Board of Directors, and shall keep a written record of all actions taken by it.

Section 10. Compensation. The Board of Directors may establish such compensation for, and reimbursement of the expenses of, directors for attendance at meetings of the Board of Directors or committees, or for other services by directors to the Corporation, as the Board of Directors may determine.

Section 11. Rules. The Board of Directors may adopt such special rules and regulations for the conduct of their meetings and the management of the affairs of the Corporation as they may deem proper, not inconsistent with law or these By-laws.

ARTICLE III

NOTICES

Section 1. Generally. Whenever by law or under the provisions of the Certificate of Incorporation or these By-laws, notice is required to be given to any director or stockholder, it shall not be construed to mean personal notice, but such notice may be given in writing, by mail, addressed to such director or stockholder, at his address as it appears on the records of the Corporation, with postage thereon prepaid, and such notice shall be deemed to be given at the time when the same shall be deposited in the United States mail. Notice to directors may also be given by telegram or telephone.

Section 2. Waivers. Whenever any notice is required to be given by law or under the provisions of the Certificate of Incorporation or these By-laws, a waiver thereof in writing, signed by the person or persons entitled to such notice, whether before or after the time of the event for which notice is to be given, shall be deemed equivalent to such notice. Attendance of a person at a meeting shall constitute a waiver of notice of such meeting, except when the person attends a meeting for the express purpose of objecting, at the beginning of the meeting, to the transaction of any business because the meeting is not lawfully called or convened.

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ARTICLE IV

OFFICERS

Section 1. Generally. The primary officers of the Corporation shall be elected by the Board of Directors and shall consist of a Chairman (who, unless the Board of Directors specifies otherwise, will also be the Chief Executive Officer), a President, a Secretary and a Treasurer. The Board of Directors may also choose any or all of the following: and one or more Vice Presidents and one or more Assistant Secretaries and Assistant Treasurers. The President may appoint one or more Vice Presidents and such other officers as the President may determine. Any number of offices may be held by the same person.

Section 2. Compensation. The compensation of all officers and agents of the Corporation who are also directors of the Corporation shall be fixed by the Board of Directors. The Board of Directors may delegate the power to fix the compensation of other officers and agents of the Corporation to an officer of the Corporation.

Section 3. Succession. The officers of the Corporation shall hold office until their successors are elected and qualified. Any officer elected or appointed by the Board of Directors or the President may be removed at any time by the affirmative vote of a majority of the directors. Any officer appointed by the President may be removed by the President. Any vacancy occurring in any office of the Corporation may be filled by the Board of Directors. Any vacancy occurring in any office of the Corporation where the officer was appointed by the President may be filled by the President.

Section 4. Authority and Duties. Each of the officers of the Corporation shall have such authority and shall perform such duties as are customarily incident to their respective offices, or as may be specified from time to time by the Board of Directors in a resolution which is not inconsistent with these By-laws, or as may be specified from time to time by the President appointing such officers.

Section 5. Chairman. The Chairman shall preside at all meetings of the stockholders and of the Board of Directors and he shall have such other duties and responsibilities as may be assigned to him by the Board of Directors. The Chairman may delegate to any qualified person authority to chair any meeting of the stockholders, either on a temporary or a permanent basis.

Section 6. President. The President shall be responsible for the active management and direction of the business and affairs of the Corporation. In case of the inability or failure of the Chairman to perform the duties of that office, the President shall perform the duties of the Chairman, unless otherwise determined by the Board of Directors.

Section 7. Execution of Documents and Action with Respect to Securities of Other Corporations. The President shall have and is hereby given, full power and authority, except as otherwise required by law or directed by the Board of Directors, (a) to execute, on behalf of the Corporation, all duly authorized contracts, agreements, deeds, conveyances or other

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obligations of the Corporation, applications, consents, proxies and other powers of attorney, and other documents and instruments, and (b) to vote and otherwise act on behalf of the Corporation, in person or by proxy, at any meeting of stockholders (or with respect to any action of such stockholders) of any other corporation in which the Corporation may hold securities and otherwise to exercise any and all rights and powers which the Corporation may possess by reason of its ownership of securities of such other corporation. In addition, the President may delegate to other officers, employees and agents of the Corporation the power and authority to take any action which the President is authorized to take under this Section 7, with such limitations as the President may specify; such authority so delegated by the President shall not be re-delegated by the person to whom such execution authority has been delegated.

Section 8. Vice-President. Each Vice President, or other officer, however titled, shall perform such duties and services and shall have such authority and responsibilities as shall be assigned to or required from time to time by the Board of Directors or the President.

Section 9. Secretary and Assistant Secretaries. (a) The Secretary shall attend all meetings of the stockholders and all meetings of the Board of Directors and record all proceedings of the meetings of the stockholders and of the Board of Directors and shall perform like duties for the standing committees when requested by the Board of Directors or the President. The Secretary shall give, or cause to be given, notice of all meetings of the stockholders and meetings of the Board of Directors. The Secretary shall perform such duties as may be prescribed by the Board of Directors or the President. The Secretary shall have charge of the seal of the Corporation and authority to affix the seal to any instrument. The Secretary or any Assistant Secretary may attest to the corporate seal by handwritten or facsimile signature. The Secretary shall keep and account for all books, documents, papers and records of the Corporation except those for which some other officer or agent has been designed or is otherwise properly accountable. The Secretary shall have authority to sign stock certificates.

(b) Assistant Secretaries, in the order of their seniority, shall assist the Secretary and, if the Secretary is unavailable or fails to act, perform the duties and exercise the authorities of the Secretary.

Section 10. Treasurer and Assistant Treasurers. (a) The Treasurer shall have the custody of the funds and securities belonging to the Corporation and shall deposit all moneys and other valuable effects in the name and to the credit of the Corporation in such depositories as may be designated by the Treasurer with the prior approval of the Board of Directors or the President. The Treasurer shall disburse the funds and pledge the credit of the Corporation as may be directed by the Board of Directors and shall render to the Board of Directors and the President, as and when required by them, or any of them, an account of all transactions by the Treasurer.

(b) Assistant Treasurers, in the order of their seniority, shall assist the Treasurer and, if the Treasurer is unable or fails to act, perform the duties and exercise the powers of the Treasurer.

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ARTICLE V

STOCK

Section 1. Certificates. The shares of the Corporation’s stock may be certificated or uncertificated, as provided under Delaware law and shall be entered into the records of the Corporation as the shares are issued. Certificates shall be numbered and their issuance and the issuance of uncertificated shares shall be recorded in the books of the Corporation. Certificates shall exhibit the holder’s name and the number of shares and shall be signed by, or in the name of the Corporation by the Chairman of the Board or the President or any Vice President and by the Secretary or an Assistant Secretary or the Treasurer or an Assistant Treasurer of the Corporation. The Secretary or any Assistant Secretary of the Corporation shall attest to the corporate seal in such certificates. Any or all of the signatures and the seal of the Corporation, if any, upon such certificates may be facsimiles, engraved or printed.

Section 2. Transfer. Upon surrender to the Corporation or the transfer agent of the Corporation of a certificate for shares duly endorsed or accompanied by proper evidence of succession, assignment or authority to transfer, it shall be the duty of the Corporation to issue, or to cause its transfer agent to issue, a new certificate or uncertificated shares to the person entitled thereto, cancel the old certificate and record the transaction upon its books. Upon the receipt of proper transfer instructions from the registered owner of uncertificated shares, such uncertificated shares shall be cancelled, issuance of new equivalent uncertificated shares or certificated shares shall be made to the shareholder entitled thereto and the transaction shall be recorded upon the records of the Corporation.

Section 3. Lost, Stole or Destroyed Certificates. The Secretary may direct a new certificate or certificates theretofore issued by the Corporation or uncertificated shares in place of any certificate or certificates theretofore issued, alleged to have been lost, stolen or destroyed upon the making of an affidavit of that fact, satisfactory to the Secretary, by the person claiming the certificate of stock to be lost, stolen or destroyed. As a condition precedent to the issuance of a new certificate or certificates or uncertificated shares in place of any certificate theretofore issued, the Secretary may require the owner of such lost, stolen or destroyed certificate or certificates to give the Corporation a bond in such sum and with such surety or sureties as the Secretary may direct as indemnity against any claims that may be made against the Corporation with respect to the certificate alleged to have been lost, stolen or destroyed or the issuance of the new certificate or uncertificated shares.

ARTICLE VI

INDEMNIFICATION

Section 1. Indemnification. The Corporation will indemnify and hold harmless to the fullest extent permitted by applicable law as it presently exists or may hereafter be amended, any person who was or is made or is threatened to be made a party or is otherwise involved in any action, suit, or proceeding, whether civil, criminal, administrative, or

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investigative (a “Proceeding”), by reason of the fact that he or she, or a person for whom he or she is the legal representative, is or was a director or officer of the Corporation or, while a director or officer of the Corporation, is or was serving at the request of the Corporation as a director, officer, employee, or agent of another corporation, partnership, joint venture, trust, enterprise, or nonprofit entity, including service with respect to employee benefit plans, against all liability and loss suffered and expenses (including attorneys’ fees) reasonably incurred by such person. Notwithstanding the preceding sentence, except for claims for indemnification (following the final disposition of such Proceeding), the Corporation will be required to indemnify a person in connection with a Proceeding (or part thereof) commenced by such person only if the commencement of such Proceeding (or part thereof) by the person was authorized in the specific case by the Board of Directors.

Section 2. Advancement of Expenses. The Corporation will pay the expenses (including attorneys’ fees) incurred by a director or officer of the Corporation in defending any Proceeding in advance of its final disposition, upon receipt of an undertaking by or on behalf of such person to repay all amounts advanced if it will ultimately be determined by final judicial decision from which there is no further right to appeal that such person is not entitled to be indemnified for such expenses under this Section 2 or otherwise. Payment of such expenses incurred by such person, may be made by the Corporation, subject to such terms and conditions as the President or Secretary of the Corporation in his or her discretion deems appropriate.

Section 3. Non-Exclusivity of Rights. The rights conferred on any person by this Article VI will not be exclusive of any other right which such person may have or hereafter acquire under any statute, provision of the Certificate of Incorporation, these by-laws, agreement, vote of stockholders or disinterested directors, or otherwise, both as to action in his or her official capacity and as to action in another capacity while holding office. The Corporation is specifically authorized to enter into individual contracts with any or all of its directors, officers, employees, or agents respecting indemnification and advances, to the fullest extent not prohibited by the Delaware General Corporation Law.

Section 4. Other Indemnification. The Corporation’s obligation, if any, to indemnify any person who was or is serving at its request as a director, officer, employee, or agent of another corporation, partnership, joint venture, trust, enterprise, or nonprofit entity will be reduced by any amount such person may collect as indemnification from such other corporation, partnership, joint venture, trust, enterprise, or nonprofit entity.

Section 5. Insurance. The Corporation may purchase and maintain insurance on behalf of any person who is or was a director, officer, employee, or agent of the Corporation, or is or was serving at the request of Corporation as a director, officer, employee, or agent of another corporation, partnership, joint venture, trust, enterprise, or nonprofit entity against any liability asserted against him or her and incurred by him or her in any such capacity, or arising out of his or her status as such, whether or not the Corporation would have the power to indemnify him or her against such liability under the provisions of the Delaware General Corporation Law.

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Section 6. Repeal, Amendment, or Modification. Any amendment, repeal, or modification of this Article VI will not adversely affect any right or protection hereunder of any person in respect of any act or omission occurring prior to the time of such repeal or modification.

ARTICLE VII

GENERAL PROVISIONS

Section I. Fiscal Year. The fiscal year of the Corporation shall be fixed from time to time by the Board of Directors.

Section 2. Corporate Seal. The Board of Directors may adopt a corporate seal and use the same by causing it or a facsimile thereof to be impressed or affixed or reproduced or otherwise.

Section 3. Reliance upon Books, Reports and Records. Each director, each member of a committee designated by the Board of Directors, and each officer of the Corporation shall, in the performance of his or her duties, be fully protected in relying in good faith upon the records of the Corporation and upon such information, opinions, reports or statements presented to the Corporation by any of the Corporation’s officers or employees, or committees of the Board of Directors, or by any other person as to matters the director, committee member or officer believes are within such other person’s professional or expert competence and who has been selected with reasonable care by or on behalf of the Corporation.

Section 4. Time Periods. In applying any provision of these By-laws which requires that an act be done or not be done a specified number of days prior to an event or that an act be done during a period of a specified number of days prior to an event, calendar days shall be used, the day of the doing of the act shall be excluded and the day of the event shall be included.

Section 5. Dividends. The Board of Directors may from time to time declare and the Corporation may pay dividends upon its outstanding shares of capital stock, in the manner and upon the terms and conditions provided by law and the Certificate of Incorporation.

Section 6. Certain Defined Terms. Terms used herein with initial capital letters that are not otherwise defined in these By-laws are used herein as defined in the Certificate of Incorporation.

ARTICLE VIII

AMENDMENTS

Section 1. Amendments. These By-laws may be altered, amended or repealed, or new by-laws may be adopted, by the stockholders or by the Board of Directors.

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