UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13D/A

                    Under the Securities Exchange Act of 1934
                               (Amendment No. 4)*

                        CARPENTER TECHNOLOGY CORPORATION
        -----------------------------------------------------------------
                                (Name of Issuer)

                     Common Stock, par value $5.00 per share
        -----------------------------------------------------------------
                         (Title of Class of Securities)

                                   144285 10 3
                       -----------------------------------
                                 (CUSIP Number)

                                 John A. Martin
                           c/o PNC Advisors - Hawthorn
                           249 Fifth Avenue, 2nd Floor
                              Pittsburgh, PA 15222
                                 (412) 762-2766
        -----------------------------------------------------------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                                February 21, 2006
             -------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  which is the subject of this  Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), 13d-1(f) or 13d-1(g), check the following box
[ ].

Note:  Schedules  filed in paper format shall include a signed original and five
copies of the  schedule,  including  all exhibits.  See  ss.240.13d-7  for other
parties to whom copies are to be sent.

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for  any  subsequent   amendment   containing   information  which  would  alter
disclosures provided in a prior cover page.



CUSIP NO. 144285 10 3                                         Page 2 of 6 Pages


The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).





                                                              Page 3 of 6 Pages



                                 SCHEDULE 13D/A
                                (Amendment No. 4)


CUSIP No. 144285 10 3

1.   NAME OF REPORTING PERSON     Ada E. Rossin

     I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (Entities Only)

2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP          (a)   [   ]
                                                               (b)   [ X ]
3.   SEC USE ONLY

4.   SOURCE OF FUNDS

5.   CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) or 2(e)                                  [   ]

6.   CITIZENSHIP OR PLACE OF ORGANIZATION United States Citizen

NUMBER OF         7.    SOLE VOTING POWER                          174,770
SHARES            ---------------------------------------------------------
BENEFICIALLY      8.    SHARED VOTING POWER                        850,100
OWNED BY          ---------------------------------------------------------
EACH              9.    SOLE DISPOSITIVE POWER                     174,770
REPORTING         ---------------------------------------------------------
PERSON WITH       10.   SHARED DISPOSITIVE POWER                   850,100
                  ---------------------------------------------------------

11.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
     PERSON       1,024,870
                  ---------------------------------------------------------

12.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
     CERTAIN SHARES                    [   ]

13.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)            4.05%
                                                                  ---------
14.  TYPE OF REPORTING PERSON    IN





CUSIP NO. 144285 10 3                                         Page 4 of 6 Pages



          This Schedule 13D/A,  Amendment No. 4 (the "Amendment") relates to the
common stock, par value $5.00 per share ("Common Stock") of Carpenter Technology
Corporation  ("CTC").  Except as specifically  set forth in this Amendment,  the
Schedule 13D, as amended on November 5, 2004,  May 26, 2005 and November 7, 2005
(the "Schedule 13D"), remains unmodified.


Item 5. Interest in Securities of the Issuer.

Items 5(a),  (b) and (e) of the Schedule 13D are hereby  amended and restated to
read as set forth below. Items 5(c)-(d) remain unchanged.

          (a) Ada E.  Rossin may be deemed to  indirectly  beneficially  own (i)
40,000  shares of CTC Common Stock as co-trustee of two trusts (the "Trusts) for
the benefit of her two grandchildren, (ii) 810,100 shares of CTC Common Stock as
co-trustee  and lifetime  beneficiary of the Ada E. Rossin  Revocable  Trust and
(iii) 174,770  shares of CTC Common Stock as trustee and  beneficiary of the Ada
E.  Rossin  QTIP  Trust.  Accordingly,  Ada E.  Rossin  may be  deemed to be the
beneficial  owner  of a  total  of  1,024,870  shares  of CTC  Common  Stock  or
approximately 4.05% of the outstanding shares of CTC Common Stock.

          (b) Ada E.  Rossin  has sole  voting  and  dispositive  power over the
174,770 shares of CTC Common Stock in the Ada E. Rossin QTIP Trust. In addition,
Ada E. Rossin has shared voting and dispositive  power over 40,000 shares of CTC
Common Stock in the Trusts and the 810,100 shares in the Ada E. Rossin Revocable
Trust.

          (e) On February 21, 2006, the reporting person, Ada E. Rossin,  ceased
to be the beneficial  owner of more than five percent of the outstanding  shares
of CTC Common Stock.


Item 7. Material to be Filed as Exhibits.

         Exhibit No.           Description
         -----------           -----------

            24.1               Power of Attorney (incorporated by reference from
                               Exhibit 24.1 to the amended Schedule 13D filed by
                               Ada E. Rossin on November 5, 2004).







CUSIP NO. 144285 10 3                                         Page 5 of 6 Pages



                                    Signature


          After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete,  and
correct.


Dated: February 22, 2006
                                       /s/ John A. Martin
                                       ------------------------------------
                                       John A. Martin, Attorney-in-Fact for
                                       Ada E. Rossin





CUSIP NO. 144285 10 3                                         Page 6 of 6 Pages




                                  Exhibit Index
                                  -------------


      Exhibit No.              Description
      -----------              -----------

         24.1                  Power of Attorney (incorporated by reference from
                               Exhibit 24.1 to the amended Schedule 13D filed by
                               Ada E.Rossin on November 5, 2004).