<PAGE>
   
                                                                   Exhibit 4(i)
    
     THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE SOLD, ASSIGNED OR TRANSFERRED
WITHOUT AN EFFECTIVE REGISTRATION STATEMENT FOR SUCH SECURITIES UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, UNLESS THE COMPANY HAS RECEIVED THE WRITTEN
OPINION OF COUNSEL SATISFACTORY TO THE COMPANY TO THE EFFECT THAT SUCH SALE,
ASSIGNMENT OR TRANSFER DOES NOT INVOLVE A TRANSACTION REQUIRING REGISTRATION OF
SUCH SECURITIES UNDER THE SECURITIES ACT OF 1933, AS AMENDED.



   
Issue Date:    September 16, 1996
Void After:    September 16, 1999            Right to Purchase 6,000
                                             Shares of Common Stock 
                                             (subject to adjustment)
                                             of Nuclear Metals, Inc.
    

                              NUCLEAR METALS, INC.
                          COMMON STOCK PURCHASE WARRANT
   
     THIS CERTIFIES that, in consideration of value received, Melvin B. Chrein
(the "Holder"), is entitled, upon the terms and subject to the conditions
hereinafter set forth, to subscribe for and purchase from Nuclear Metals, Inc.,
a Massachusetts corporation (the "Company"), Six Thousand (6,000) fully paid 
and nonassessable shares of the Company's Common Stock, $0.10 par value per 
share (the "Common Stock").  The number and exercise price of the securities 
that may be purchased upon the exercise of this Common Stock Purchase Warrant 
(the "Warrant") are subject to adjustment as provided herein.
    
     1.   EXERCISE PERIOD AND PRICE - The purchase rights represented by this
Warrant are exercisable by the Holder, in whole or in part, at any time from
time to time during the Exercise Period at the Exercise Price.  The Exercise
Price shall initially be $15.00 per share of Common Stock subject to adjustment
as hereinafter provided.  

     The Exercise Period shall commence at 9:00 a.m. Boston, Massachusetts time
on September 16, 1996 and shall end at 5:00 p.m. Boston, Massachusetts time on
September 16,  1999.  

     2.   EXERCISE OF WARRANT - During the Exercise Period and provided this
Warrant has not been terminated, this Warrant shall be exercised, in whole or in
part and from time to time, by the surrender of this Warrant and the Notice of
Exercise annexed hereto duly executed at the principal office of the Company, in
Boston, Massachusetts (or such other office or agency of the Company as it may
designate) and upon payment of the Exercise Price of the shares thereby
purchased (payment to be by check or bank draft payable to the order of the
Company).  If the amount of the payment received by the Company is less than


<PAGE>

the Exercise Price, the Holder will be notified of the deficiency and shall make
payment in that amount within three days.  In the event the payment exceeds the
Exercise Price, the Company will refund the excess to the holder within three
days of receipt.  Upon exercise, the Holder shall be entitled to receive, within
a reasonable time after payment in full, one or more certificates, issued in the
Holder's name or in such name or names as the Holder may direct, subject to the
limitations on transfer contained herein, for the number of shares of Common
Stock so purchased.  The shares so purchased shall be deemed to be issued as of
the close of business on the date on which this Warrant shall have been
exercised.

     The Company covenants that all shares of Common Stock that are issued upon
the exercise of rights represented by this Warrant will be fully paid,
nonassessable, and free from all taxes, liens and charges in respect of the
issue thereof (other than taxes in respect of any transfer occurring
contemporaneously with such issue).

     3.   NO FRACTIONAL SHARES OR SCRIP - No fractional shares or scrip
representing fractional shares shall be issued upon the exercise of this
Warrant.  In lieu thereof, a cash payment shall be made equal to such fraction
multiplied by the Exercise Price per share as then in effect.

     4.   CHARGES, TAXES AND EXPENSES - Issuance of certificates for shares of
Common Stock upon the exercise of this Warrant shall be made without charge to
the Holder for any issue or transfer tax or other incidental expense in respect
of the issuance of such certificate, all of which taxes and expenses shall be
paid by the Company.

     5.   NO RIGHTS AS SHAREHOLDER - This Warrant does not entitle the Holder to
any voting rights or other rights as a shareholder of the Company prior to
exercise and payment of the Exercise Price in accordance with Section 2 hereof. 

     6.   SALE OR TRANSFER OF THE WARRANT; LEGEND - This Warrant shall not be
sold or transferred unless either (i) it first shall have registered under the
1933 Act and any applicable state securities laws, or (ii) the Company first
shall have been furnished with an opinion of legal counsel reasonably
satisfactory to the Company to the effect that such sale or transfer is exempt
from the registration requirements of the 1933 Act and such state laws.  Each
certificate representing any Warrant that has not been registered and that has
not been sold pursuant to an exemption that permits removal of the legend shall
bear a legend substantially in the form of the legend affixed to this Warrant.

Upon the request of a holder of a certificate representing any Warrant, the
Company shall remove the foregoing legend from the certificate or issue to such
holder a new certificate therefor free of any transfer legend, if, with such
request, the Company shall have received either (i) an opinion of counsel
reasonably satisfactory to the Company to the effect that such legend may be
removed from such certificate or (ii) if the present Paragraph (k) of Rule 144
or a substantially similar successor rule remains in force and effect,
representations from the holder that such holder is not then, and has not been
during the preceding three months, an 


                                      -2-

<PAGE>

affiliate of the Company and that such holder has beneficially owned the 
security (within the meaning of Rule 144) for three years or more.

     Such Warrant may be subject to additional restrictions on transfer imposed
under applicable state and federal securities law.

     7.   ADJUSTMENTS

          7.1  ADJUSTMENTS FOR STOCK SPLITS, REVERSE STOCK SPLITS AND STOCK
DIVIDENDS -  In the event that the outstanding shares of Common Stock shall be
subdivided (split), combined (reverse split), by reclassification or otherwise,
or in the event of any dividend payable on the Common Stock in shares of Common
Stock, the number of shares of Common Stock available for purchase in effect
immediately prior to such subdivision, combination, or dividend shall be
proportionately adjusted. 

          7.2  ADJUSTMENT FOR CAPITAL REORGANIZATIONS - If at any time there
shall be a capital reorganization of the Company or a merger or consolidation of
the Company with or into another corporation, or the sale of the Company's
properties and assets as, or substantially as, an entirety to any other person,
then, as part of such reorganization, merger, consolidation, or sale, lawful
provision shall be made so that the Holder of this Warrant shall thereafter be
entitled to receive on exercise of this Warrant during the period specified in
this Warrant and on payment of the Exercise Price then in effect, the number of
shares of stock or other securities or property of the Company, or of the
successor corporation resulting from such merger or consolidation, to which a
holder of the Common Stock deliverable on exercise of this Warrant would have
been entitled on such capital reorganization, merger, consolidation, or sale if
this Warrant had been exercised immediately before that capital reorganization,
merger, consolidation, or sale.  In any such case, appropriate adjustment, as
determined in good faith by the Board of Directors of the Company, shall be made
in the application of the provisions of this Warrant with respect to the rights
and interests of the Holder of this Warrant after the reorganization, merger,
consolidation, or sale to the end that the provisions of this Warrant (including
adjustment of the number of shares purchasable on exercise of this Warrant)
shall be applicable after that event, as near as reasonably may be, in relation
to any shares or other securities or property deliverable after that event on
exercise of this Warrant.

          7.3  CERTIFICATE AS TO ADJUSTMENTS - Upon the occurrence of each
adjustment or readjustment pursuant to this Section 7, the Company at its
expense shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and furnish to each Holder a certificate setting forth
such adjustment or readjustment and showing in detail the facts upon which such
adjustment or readjustment is based.  The Company shall, upon the written
request, at any time, of any Holder, furnish or cause to be furnished to such
Holder, a like certificate setting forth:  (i) such adjustments and
readjustments; (ii) the Exercise Price at the time in effect; and (iii) the
number of shares of Common Stock and the 


                                      -3-

<PAGE>

amount, if any, of other property that at the time would be received upon the
exercise of the Warrant.

          7.4  NOTICES OF RECORD DATE - In the event of any taking by the
Company of a record of the holders of any class of securities for the purpose of
determining the holders thereof who are entitled to receive any dividend (other
than a cash dividend that is the same as cash dividends paid in previous
quarters) or other distribution, the Company shall mail to each Holder at least
ten days prior to the date specified for the taking of a record, a notice
specifying the date on which any such record is to be taken for the purpose of
such dividend or distribution.

     8.   RESERVATION OF STOCK, ETC., ISSUABLE ON EXERCISE OF WARRANT - The
Company will at all times reserve and keep available, solely for issuance and
delivery upon the exercise of this Warrant, all shares of Common Stock (or other
securities) from time to time issuable upon the exercise of this Warrant and all
shares of Common Stock issuable upon conversion of such shares of Common Stock.

     9.   LOSS, THEFT, DESTRUCTION OR MUTILATION OF WARRANT - Upon receipt by
the Company of evidence reasonably satisfactory to it of the loss, theft,
destruction, or mutilation of this Warrant, and in case of loss, theft, or
destruction, of indemnity or security reasonably satisfactory to it, and upon
reimbursement to the Company of all reasonable expenses incidental thereto, and
upon surrender and cancellation of this Warrant, if mutilated, the Company will
make and deliver a new Warrant of like tenor and dated as of such cancellation
in lieu of this Warrant.


     10.  REMEDIES - The Company stipulates that the remedies at law of the
holder of this Warrant in the event of any default or threatened default by the
Company in the performance of or compliance with any of the terms of this
Warrant are not adequate and may be enforced by a decree for the specific
performance of any agreement contained herein or by an injunction against a
violation of any of the terms hereof or otherwise.

     11.  NOTICES, ETC. - All notices and other communications from the Company
to the holder of this Warrant shall be mailed, by first class mail, to such
address as may have been furnished to the Company in writing by such holder, or,
until an address is so furnished, to and at the address of the last holder of
this Warrant who has so furnished an address to the Company.  All communications
from the holder of this Warrant to the Company shall be mailed by first class
mail to the Company's principal office, or such other address as may have been
furnished to the holder in writing by the Company.

     12.  MISCELLANEOUS - This Warrant shall be construed and enforced in
accordance with and governed by the laws of The Commonwealth of Massachusetts. 
The headings in this Warrant are for purposes of reference only, and shall not
limit or otherwise affect any of the terms hereof.


                                      -4-

<PAGE>

     IN WITNESS WHEREOF, the Company has caused this Warrant to be executed in
its corporate name by its duly authorized officer and to be dated as of the
issue date set forth on the first page of this Warrant.

                                   NUCLEAR METALS, INC.

   
                                   By: /s/ James M. Spiezio
                                      --------------------------------------
                                       Vice President, Finance
[CORPORATE SEAL]         
    
Attest:

   
/s/ Thomas A. Wooters
------------------------------
Clerk
    

                                      -5-

<PAGE>

                          NOTICE OF EXERCISE OF COMMON
                             STOCK PURCHASE WARRANT


TO:   Nuclear Metals, Inc.

     (1)  Pursuant to the terms of the attached Warrant, the undersigned hereby
elects to purchase ______ shares of Common Stock of Nuclear Metals, Inc. (the
"Company"), and either (i) tenders herewith payment of the Exercise Price of
such shares in full or (ii) by indicating "cashless exercise" below, directs
that payment of the Exercise Price be made by cancellation as of the date of
exercise of a portion of this Warrant having a net fair market value equal to
the Exercise Price.

     (2)  Please issue a certificate or certificates representing said shares of
Common Stock, in the name of the undersigned or in such other name(s) as is/are
specified immediately below or, if necessary, on an attachment hereto:

               NAME                          ADDRESS
               ----                          -------






     (3)  In the event of partial exercise, please reissue an appropriate
Warrant exercisable into the remaining shares.




DATE: ____________________               HOLDER: _____________________________



Check here if cashless exercise: ______ 



<PAGE>

   

                          SCHEDULE TO EXHIBIT 4(i)


     Other Similar Common Stock Purchase Warrants of the Company dated 
September 16, 1996:


               HOLDER                          # OF SHARES
               ------                          -----------

1.  Charles Alpert or nominee                     13,500
2.  Marshall J. Chrein                             1,500