Exhibit 10.6


 


FORM
OF


LOCK-UP
AGREEMENT


 


[    
  ], 2018


 


Hennessy
Capital Acquisition Corp. III


3500
Sunrise Highway


Suite
200, Building 200


Great
River, New York 11739


 


Ladies
and Gentlemen:


 


This
letter agreement (this “Agreement”) relates to a Purchase Agreement entered into as of June 25, 2018 (“Purchase
Agreement”) by and between Hennessy Capital Acquisition Corp. III, a Delaware corporation (“Purchaser”),
and JFL-NRC-SES Partners, LLC, a Delaware limited liability company. Capitalized terms used and not otherwise defined herein are
defined in the Purchase Agreement and shall have the meanings given to such terms in the Purchase Agreement.


 


1.  In
order to induce all parties to consummate the transactions contemplated by the Purchase Agreement, the undersigned hereby agrees
that, from the date hereof until the earliest of: (a) the 180th day after the Closing Date, (b) the date
following the completion of the transactions contemplated by the Purchase Agreement on which Purchaser completes a liquidation,
merger, stock exchange or other similar transaction that results in all of Purchaser’s stockholders having the right to
exchange their shares of Purchaser Common Stock for cash, securities or other property and (c) the Alternative Lock-up Termination
Date (as defined in the Exchange and Forfeiture Agreement) (the period between the Closing Date and the earliest of clauses (a),
(b) and (c), the “Lock-Up Period”), the undersigned will not: (i) sell, offer to sell, contract or agree
to sell, hypothecate, pledge, grant any option to purchase or otherwise dispose of or agree to dispose of, directly or indirectly,
or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16
of the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Securities and Exchange Commission promulgated
thereunder (the “Exchange Act”), with respect to the shares of Purchaser Common Stock received as Purchase
Price Common Stock pursuant to the Purchase Agreement (such shares, collectively, the “Lock-up Shares”), (ii) enter
into any swap or other arrangement that transfers to another, in whole or in part, any of the economic consequences of ownership
of any of the Lock-up Shares, in cash or otherwise, or (iii) publicly announce any intention to effect any transaction specified
in clause (i) or (ii).


 


2.  The
undersigned hereby authorizes Purchaser during the Lock-Up Period to cause its transfer agent for the Lock-up Shares to decline
to transfer, and to note stop transfer restrictions on the stock register and other records relating to, Lock-up Shares for which
the undersigned is the record holder and, in the case of Lock-up Shares for which the undersigned is the beneficial but not the
record holder, agrees during the Lock-Up Period to cause the record holder to cause the relevant transfer agent to decline to
transfer, and to note stop transfer restrictions on the stock register and other records relating to, such Lock-up Shares, if
such transfer would constitute a violation or breach of this Agreement.


 






    


    


    

 


3.  Notwithstanding
the foregoing, the undersigned may sell or otherwise transfer Lock-up Shares during the undersigned’s lifetime or on death
(or, if the undersigned is not a natural person, during its existence) (i) if the undersigned is not a natural person, to
its direct or indirect equity holders or to any of its other Affiliates, (ii) to the immediate family members (including
spouses, significant others, lineal descendants, brothers and sisters) of the undersigned, (iii) to a family trust, foundation
or partnership established for the exclusive benefit of the undersigned, its equity holders or any of their respective immediate
family members, or (iv) to a charitable foundation controlled by the undersigned, its equityholders or any of their respective
immediate family members; provided, however, that in each such case, any such sale or transfer shall be conditioned upon entry
by such transferees into a written agreement, addressed to Purchaser, agreeing to be bound by these transfer restrictions and
the other terms and conditions of this Agreement.


  


4.  The
undersigned hereby represents and warrants that the undersigned has full power and authority to enter into this Agreement and
that this Agreement constitutes the legal, valid and binding obligation of the undersigned, enforceable in accordance with its
terms. Upon request, the undersigned will execute any additional documents necessary in connection with enforcement hereof. Any
obligations of the undersigned shall be binding upon the successors and assigns of the undersigned from the date first above written.


 


5.  This
Agreement constitutes the entire agreement and understanding of the parties hereto in respect of the subject matter hereof and
supersedes all prior understandings, agreements, or representations by or among the parties hereto, written or oral, to the extent
they relate in any way to the subject matter hereof. This Agreement may not be changed, amended, modified or waived (other than
to correct a typographical error) as to any particular provision, except by a written instrument executed by all parties hereto.


 


6.  No
party hereto may assign either this Agreement or any of its rights, interests, or obligations hereunder without the prior written
consent of the other party. Any purported assignment in violation of this paragraph shall be void and ineffectual and shall not
operate to transfer or assign any interest or title to the purported assignee. This Agreement shall be binding on the undersigned
and its successors and assigns.


 


7.  This
Agreement shall be governed by and construed and enforced in accordance with the laws of the State of Delaware, without giving
effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction. The
parties hereto (i) all agree that any action, proceeding, claim or dispute arising out of, or relating in any way to, this
Agreement shall be brought and enforced in the Court of Chancery of the State of Delaware (or, if the Court of Chancery of the
State of Delaware lacks jurisdiction, then in the applicable Delaware state court), or if under applicable Law exclusive jurisdiction
of such action is vested in the federal courts, then the United States District Court for the District of Delaware courts, and
irrevocably submits to such jurisdiction and venue, which jurisdiction and venue shall be exclusive, and (ii) waives any
objection to such exclusive jurisdiction and venue or that such courts represent an inconvenient forum.


 


8.  Any
notice, consent or request to be given in connection with any of the terms or provisions of this Agreement shall be in writing
and shall be sent by express mail or similar private courier service, by certified mail (return receipt requested) or email transmission
to the address or email address (as applicable) set forth below such party’s name on the signature page hereto.


 


[Signature
on the following page]


 






    	 	2	 



    


    

 





	 	Very
    truly yours,
	 	 
	 	JFL-NRC-SES
    Partners, LLC
	 	 	 
	 	By:	
	 	 	Name:
	 	 	Title:
	 	 	 
	 	Address:	
	 	 	 
	 	 	 
	 	 	 
	 	Email:	 
	 	 
	Accepted
    and Agreed:	 	 
	 	 	 
	 	PURCHASER
	 	 
	 	HENNESSY
    CAPITAL ACQUISITION CORP. III
	 	 	 
	 	By:	
	 	 	Name:
	 	 	Title:
	 	 	 
	 	Address:	3500 Sunrise
    Highway
	 	 	Suite 200,
    Building 200
	 	 	Great River,
    New York 11739
	 	 	Attention:
    Secretary
	 	 	 
	 	Email:	




 


[Signature Page to Lock-Up Agreement]