<PAGE>   1

                                                                     EXHIBIT 4.1

                              [SIMCALA LETTERHEAD]




April 18, 2001

The Bank of New York
101 Barclay Street, 21st Floor
New York, New York 10286


         Re:  Notice of Defaulted Interest Payment and Officer's Certificate

Ladies and Gentlemen:

Pursuant to Section 4.04 of the Indenture (the "Indenture") dated as of March
31, 1998 by and between SAC Acquisition Corp., as Acquirer of Simcala, Inc.
(the "Company"), and The Bank of New York (as successor trustee to IBJ Schroder
Bank & Trust Company)(the "Trustee"), the Company hereby notifies Trustee that
the Company has defaulted on the payment of interest due on the 9-5/8% Senior
Notes due 2006 (the "Notes"). The present installment of interest on the Notes
was due on or before April 16, 2001. Enclosed please find an Officers'
Certificate executed by C. Edward Boardwine and R. Myles Cowan describing the
nature of the default and the action the Company intends to take with respect
thereto.

Please note that Section 6.01(a) of the Indenture provides that failure to make
a timely payment of the interest due on the Notes does not constitute an Event
of Default unless such default continues for a period of 30 days. The Company
proposes to make a payment of all of the defaulted interest, plus interest
payable on the defaulted interest (at the rate of 10-5/8% per annum), on each
Note on Tuesday, May 15, 2001 (the "Payment Date"). The special record date for
payment of the defaulted interest, and for interest payable on the defaulted
interest, shall be Friday, May 4, 2001 (the "Special Record Date").

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                                    SIMCALA




Pursuant to Section 2.12 of the Indenture, the Company must mail or cause the
Trustee to mail to Holders of the Notes a notice stating the Payment Date, the
Special Record Date, and the amount of interest to be paid. Enclosed please
find a proposed notice to the Holders including that information. As the notice
must be mailed no less than 15 days before the Special Record Date, we will
require your immediate assistance to distribute the notice no later than this
Thursday, April 19, 2001, and hereby request that you deliver such notice to
all Holders of recorded on such date.

Thank you for your assistance with respect to this matter.

Very truly yours,

SIMCALA, INC.


By: /s/ R. Myles Cowan
    ------------------------------------------------
    R. Myles Cowan
    Chief Financial Officer




                                     - 2 -
<PAGE>   3
                             OFFICERS' CERTIFICATE


         We, C. Edward Boardwine and R. Myles Cowan, certify that we are the
Chief Executive Officer and Chief Financial Officer, respectively, of Simcala,
Inc., a Delaware corporation (the "Company"), and that, as such, we are
authorized to execute this Officers' Certificate on behalf of the Company, and
do hereby further certify that:

         1.       We are delivering this Officers' Certificate pursuant to
                  Section 4.04(c) of that certain Indenture dated as of March
                  31, 1998 (the "Indenture") between the Company and The Bank of
                  New York, as Trustee (f/k/a IBJ Schroder Bank & Trust Company)
                  pursuant to which the Company has issued its 9-5/8% Senior
                  Notes (the "Notes");

         2.       We have reviewed the applicable provisions of the Indenture;

         3.       We have, in our opinion, made such examination and inquiry as
                  is necessary to enable us to make the certifications set forth
                  herein;

         4.       On April 16, 2001, the Company failed to make a timely payment
                  of interest on the Notes which constitutes a Default (but not
                  an Event of Default) under the Indenture;

         5.       Pursuant to Section 2.12 of the Indenture, the Company has
                  established a proposed new payment date of May 15, 2001, at
                  which time the Company intends to pay to the Holders (as that
                  term is defined in the Indenture) as of a special record date
                  of May 4, 2001, all of the defaulted interest, plus interest
                  payable on the defaulted interest calculated at a rate of
                  10-5/8% per annum;

<PAGE>   4

         6     The Company shall deliver notice specifying the special record
               date, the proposed new payment date, and the amount of interest
               to be paid to all Holders no later than Thursday, April 19, 2001;
               and

         7     The taking of the foregoing actions will cure the Default that
               has occurred within the applicable grace period set forth in the
               Indenture such that no Event of Default shall occur.

         IN WITNESS WHEREOF, we have executed this Certificate and affixed the
seal of the Company this 18th day of April, 2001.
                         ----

                                   SIMCALA, INC.


                                   By: /s/ C. Edward Boardwine
                                       -----------------------------------------
                                       C. Edward Boardwine, Chief Executive
                                       Officer


                                   By: /s/ R. Myles Cowan
                                       -----------------------------------------
                                       R. Myles Cowan, Chief Financial Officer
<PAGE>   5
                              [SIMCALA LETTERHEAD]



April 19, 2001

         RE:  9-5/8% SENIOR NOTES DUE 2006 ISSUED BY SIMCALA, INC.

To the Holders of the below-referenced Notes:

Reference is made to that certain Indenture dated as of March 31, 1998 (the
"Indenture") by and between SAC Acquisition Corp., as Acquirer of Simcala, Inc.
(the "Company"), and The Bank of New York (as successor trustee to IBJ Schroder
Bank & Trust Company) (the "Trustee"), pursuant to which the Company issued its
9-5/8% Senior Notes due 2006 (the "Notes").

On April 16, 2001, the Company failed to pay the installment of interest on the
Notes in the amount of $3,609,375.00 that was then due and payable on the Notes.

The Company intends to pay this installment of interest in full on May 15, 2001,
together with post-default interest on such past-due interest at the rate of
10-5/8% per annum. Accordingly, and pursuant to Section 2.12 of the Indenture,
the Company hereby establishes (i) a new payment date of May 15, 2001 (the
"Payment Date") for the payment of such past-due interest (and interest thereon)
and (ii) a special record date for such payment (the "Special Record Date") of
May 4, 2001. On the Payment Date, the Company intends to pay to all Holders of
record as of the Special Record Date the above amount of such past-due interest,
plus interest on the defaulted interest (calculated at the rate of 10-5/8% per
annum) equal to $31,958.01. Such payment shall be made in the same manner as
prior payments of interest on the Notes.

For further information regarding the payment, you may call The Bank of New
York at 800-438-5473.

Very truly yours,

SIMCALA, INC.


By: /s/ R. Myles Cowan
    ------------------
R. Myles Cowan
Chief Financial Officer


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P.O. Box 68                                                Phone: (334) 215-7560
Ohio Ferro-Alloys Road                                       Fax: (334) 216-8969
Mt. Meigs, Alabama 36057