<PAGE>   1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 16, 2001
                                                  REGISTRATION NO. 333-_________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                             ----------------------

                                ELECTROGLAS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

           DELAWARE                                            77-0336101
(State or Other Jurisdiction of                            (I.R.S. Employer
 Incorporation or Organization)                          Identification Number)

                          6024 SILVER CREEK VALLEY ROAD
                               SAN JOSE, CA 95138
                                 (408) 528-3000
    (Address, Including Zip Code, and Telephone Number, Including Area Code,
                  of Registrant's Principal Executive Offices)

        ELECTROGLAS, INC. AMENDED AND RESTATED 1997 STOCK INCENTIVE PLAN
                              (Full Title of Plans)

                                THOMAS E. BRUNTON
    VICE PRESIDENT-FINANCE, CHIEF FINANCIAL OFFICER, TREASURER AND SECRETARY
                                ELECTROGLAS, INC.
                          6024 SILVER CREEK VALLEY ROAD
                               SAN JOSE, CA 95138
                                 (408) 528-3000
 (Name, Address, Including Zip Code, and Telephone Number, Including Area Code,
                              of Agent for Service)

                                 ---------------

                                    Copy to:

                            WILLIAM D. SHERMAN, ESQ.
                             MORRISON & FOERSTER LLP
                               755 PAGE MILL ROAD
                            PALO ALTO, CA 94304-1018
                                 (415) 813-5600

                                 ---------------

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
  ==================================================================================================================
                                                              MAXIMUM           PROPOSED MAXIMUM        AMOUNT OF
         TITLE OF SECURITIES             AMOUNT TO        OFFERING PRICE       AGGREGATE OFFERING      REGISTRATION
          TO BE REGISTERED             BE REGISTERED       PER SHARE(1)             PRICE(1)               FEE
  ---------------------------------- ------------------ -------------------- ------------------------ ---------------
<S>                                      <C>                  <C>                <C>                        <C>
  Common Stock, $.01
  par value per share..........          700,000              $15.99             $11,193,000                $2,799
  ==================================================================================================================
</TABLE>

  (1)    Estimated solely for the purpose of calculating the registration fee in
         accordance with Rules 457(h) and 457(c) under the Securities Act of
         1933 and based upon the average of the high and low prices reported on
         the Nasdaq National Market on August 13, 2001.

         In addition, pursuant to Rule 416(c) under the Securities Act, this
         Registration Statement also covers an indeterminate amount of interests
         to be offered or sold pursuant to the employee benefit plans described
         herein.

================================================================================

<PAGE>   2



                                     PART I

                          INFORMATION REQUIRED IN THE
                            SECTION 10(a) PROSPECTUS

         The documents containing the information specified in Part 1 of Form
S-8 (plan information and registrant information and employee plan annual
information) will be sent or given to employees as specified by Securities and
Exchange Commission Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission either as part of this Registration Statement
or as prospectuses or prospectus supplements pursuant to Rule 424. These
documents and the documents incorporated by reference in this Registration
Statement pursuant to Item 3 of Form S-8 (Part II hereof), taken together,
constitute a prospectus that meets the requirements of Section 10(a) of the
Securities Act of 1933.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

         There are hereby incorporated by reference in this Registration
Statement the following documents and information previously filed with the
Securities and Exchange Commission (the "Commission"):

         1. The contents of the Registrant's Registration Statement on Form S-8,
Commission File No. 333-49303, 333-62139, 333-82209 and 333-38842, including
exhibits thereto, are hereby incorporated by reference into this Registration
Statement, except as the same may be modified by the information set forth
herein.

         2. The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 2000, filed pursuant to Section 13 of the Securities Exchange
Act of 1934 (the "Exchange Act").

         3. The Company's Quarterly Reports on Form 10-Q for the periods ended
March 31, 2001 and June 30, 2001.

         4. The description of the Company's Common Stock contained in the
Company's Registration Statement on Form 8-A filed with the Commission on April
23, 1993.

         All documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act after the date of this Registration
Statement, and prior to the filing of a post-effective amendment which indicates
that all securities offered hereby have been sold or which


<PAGE>   3

deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be a part hereof
from the date of filing of such documents.

ITEM 8. EXHIBITS.

          5.1     Opinion of Morrison & Foerster LLP

         23.1     Consent of Morrison & Foerster LLP (contained in Exhibit 5.1)

         23.2     Consent of Ernst & Young LLP, Independent Auditors

         24.1     Power of Attorney (see Signature Page)

<PAGE>   4

         SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Registrant, Electroglas, Inc., certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of San Jose, State of
California, on August 16, 2001.

                                    ELECTROGLAS, INC

                                    By:  /s/ Curtis S. Wozniak
                                       ----------------------------------------
                                       Curtis S. Wozniak
                                       Chief Executive Officer

                                POWER OF ATTORNEY

        Each person whose signature appears below constitutes and appoints
Curtis S. Wozniak and Thomas E. Brunton, and each of them, as attorneys-in-fact,
each with the power of substitution, for him in any and all capacities, to sign
any amendment to this Registration Statement and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, granting to said attorneys-in-fact, full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in connection therewith, as fully to all intents and purposes as he
might or could do in person, hereby ratifying and confirming the said
attorney-in-fact or his substitute or substitutes, may lawfully do or cause to
be done by virtue hereof

         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the date indicated.

<TABLE>
<CAPTION>
Signature                                      Capacity                        Date
---------                                      --------                        ----
<S>                                            <C>                             <C>
/s/ Curtis S. Wozniak                          Chief Executive Officer and     August 16, 2001
----------------------------------------       Director and Chairman
    Curtis S. Wozniak                          (Principal Executive Officer)
</TABLE>


<PAGE>   5
<TABLE>
<CAPTION>
Signature                                      Capacity                        Date
---------                                      --------                        ----
<S>                                            <C>                             <C>
/s/ Thomas E. Brunton                          Vice President, Finance,        August 16, 2001
----------------------------------------       Chief Financial Officer,
    Thomas E. Brunton                          Treasurer and Secretary
                                               (Principal Financial and
                                               Accounting Officer)

/s/ Neil R. Bonke                              Director                        August 16, 2001
----------------------------------------
    Neil R. Bonke

/s/ Roger D. Emerik                            Director                        August 16, 2001
----------------------------------------
    Roger D. Emerick

/s/ Robert J. Frankenberg                      Director                        August 16, 2001
----------------------------------------
    Robert J. Frankenberg

/s/ Mel Friedman                               Director                        August 16, 2001
----------------------------------------
    Mel Friedman
</TABLE>


<PAGE>   6



                                INDEX TO EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT
NUMBER                              DOCUMENT
-------                             --------
<S>               <C>
    5.1           Opinion of Morrison & Foerster LLP

   23.1           Consent of Counsel (included in Exhibit 5.1)

   23.2           Consent of Ernst & Young LLP, Independent
                  Auditors

   24.1           Power of Attorney (see Signature Page)
</TABLE>
[{"type": "S-8", "sequence": "1", "filename": "f75180s-8.txt", "description": "FORM S-8", "secsgml_size_bytes": 10874}]
{"company-data": {"conformed-name": "ELECTROGLAS INC", "cik": "0000902281", "assigned-sic": "3559", "irs-number": "770336101", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-67708", "film-number": "1717115"}, "business-address": {"street1": "2901 CORONADO DRIVE", "city": "SANTA CLARA", "state": "CA", "zip": "95054", "phone": "4087276500"}, "mail-address": {"street1": "2901 CORONADO DRIVE", "city": "SASSANTA CL", "state": "CA", "zip": "95054"}}
1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON AUGUST 16, 2001
                                                  REGISTRATION NO. 333-_________
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             ----------------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                             ----------------------

                                ELECTROGLAS, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

           DELAWARE                                            77-0336101
(State or Other Jurisdiction of                            (I.R.S. Employer
 Incorporation or Organization)                          Identification Number)

                          6024 SILVER CREEK VALLEY ROAD
                               SAN JOSE, CA 95138
                                 (408) 528-3000
    (Address, Including Zip Code, and Telephone Number, Including Area Code,
                  of Registrant's Principal Executive Offices)

        ELECTROGLAS, INC. AMENDED AND RESTATED 1997 STOCK INCENTIVE PLAN
                              (Full Title of Plans)

                                THOMAS E. BRUNTON
    VICE PRESIDENT-FINANCE, CHIEF FINANCIAL OFFICER, TREASURER AND SECRETARY
                                ELECTROGLAS, INC.
                          6024 SILVER CREEK VALLEY ROAD
                               SAN JOSE, CA 95138
                                 (408) 528-3000
 (Name, Address, Including Zip Code, and Telephone Number, Including Area Code,
                              of Agent for Service)

                                 ---------------

                                    Copy to:

                            WILLIAM D. SHERMAN, ESQ.
                             MORRISON & FOERSTER LLP
                               755 PAGE MILL ROAD
                            PALO ALTO, CA 94304-1018
                                 (415) 813-5600

                                 ---------------

                         CALCULATION OF REGISTRATION FEE
==================================================================================================================
                                                              MAXIMUM           PROPOSED MAXIMUM        AMOUNT OF
         TITLE OF SECURITIES             AMOUNT TO        OFFERING PRICE       AGGREGATE OFFERING      REGISTRATION
          TO BE REGISTERED             BE REGISTERED       PER SHARE(1)             PRICE(1)               FEE
  ---------------------------------- ------------------ -------------------- ------------------------ ---------------
Common Stock, $.01
  par value per share..........          700,000              $15.99             $11,193,000                $2,799
  ==================================================================================================================
(1)    Estimated solely for the purpose of calculating the registration fee in
         accordance with Rules 457(h) and 457(c) under the Securities Act of
         1933 and based upon the average of the high and low prices reported on
         the Nasdaq National Market on August 13, 2001.

         In addition, pursuant to Rule 416(c) under the Securities Act, this
         Registration Statement also covers an indeterminate amount of interests
         to be offered or sold pursuant to the employee benefit plans described
         herein.

================================================================================
2

                                     PART I

                          INFORMATION REQUIRED IN THE
                            SECTION 10(a) PROSPECTUS

         The documents containing the information specified in Part 1 of Form
S-8 (plan information and registrant information and employee plan annual
information) will be sent or given to employees as specified by Securities and
Exchange Commission Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission either as part of this Registration Statement
or as prospectuses or prospectus supplements pursuant to Rule 424. These
documents and the documents incorporated by reference in this Registration
Statement pursuant to Item 3 of Form S-8 (Part II hereof), taken together,
constitute a prospectus that meets the requirements of Section 10(a) of the
Securities Act of 1933.

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

         There are hereby incorporated by reference in this Registration
Statement the following documents and information previously filed with the
Securities and Exchange Commission (the "Commission"):

         1. The contents of the Registrant's Registration Statement on Form S-8,
Commission File No. 333-49303, 333-62139, 333-82209 and 333-38842, including
exhibits thereto, are hereby incorporated by reference into this Registration
Statement, except as the same may be modified by the information set forth
herein.

         2. The Registrant's Annual Report on Form 10-K for the fiscal year
ended December 31, 2000, filed pursuant to Section 13 of the Securities Exchange
Act of 1934 (the "Exchange Act").

         3. The Company's Quarterly Reports on Form 10-Q for the periods ended
March 31, 2001 and June 30, 2001.

         4. The description of the Company's Common Stock contained in the
Company's Registration Statement on Form 8-A filed with the Commission on April
23, 1993.

         All documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Exchange Act after the date of this Registration
Statement, and prior to the filing of a post-effective amendment which indicates
that all securities offered hereby have been sold or which
3

deregisters all securities then remaining unsold, shall be deemed to be
incorporated by reference in this Registration Statement and to be a part hereof
from the date of filing of such documents.

ITEM 8. EXHIBITS.

          5.1     Opinion of Morrison & Foerster LLP

         23.1     Consent of Morrison & Foerster LLP (contained in Exhibit 5.1)

         23.2     Consent of Ernst & Young LLP, Independent Auditors

         24.1     Power of Attorney (see Signature Page)
4

         SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the
Registrant, Electroglas, Inc., certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing on Form S-8 and has
duly caused this registration statement to be signed on its behalf by the
undersigned, thereunto duly authorized, in the City of San Jose, State of
California, on August 16, 2001.

                                    ELECTROGLAS, INC

                                    By:  /s/ Curtis S. Wozniak
                                       ----------------------------------------
                                       Curtis S. Wozniak
                                       Chief Executive Officer

                                POWER OF ATTORNEY

        Each person whose signature appears below constitutes and appoints
Curtis S. Wozniak and Thomas E. Brunton, and each of them, as attorneys-in-fact,
each with the power of substitution, for him in any and all capacities, to sign
any amendment to this Registration Statement and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, granting to said attorneys-in-fact, full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in connection therewith, as fully to all intents and purposes as he
might or could do in person, hereby ratifying and confirming the said
attorney-in-fact or his substitute or substitutes, may lawfully do or cause to
be done by virtue hereof

         Pursuant to the requirements of the Securities Act of 1933, this
registration statement has been signed by the following persons in the
capacities and on the date indicated.
Signature                                      Capacity                        Date
---------                                      --------                        ----
/s/ Curtis S. Wozniak                          Chief Executive Officer and     August 16, 2001
----------------------------------------       Director and Chairman
    Curtis S. Wozniak                          (Principal Executive Officer)
5
Signature                                      Capacity                        Date
---------                                      --------                        ----
/s/ Thomas E. Brunton                          Vice President, Finance,        August 16, 2001
----------------------------------------       Chief Financial Officer,
    Thomas E. Brunton                          Treasurer and Secretary
                                               (Principal Financial and
                                               Accounting Officer)

/s/ Neil R. Bonke                              Director                        August 16, 2001
----------------------------------------
    Neil R. Bonke

/s/ Roger D. Emerik                            Director                        August 16, 2001
----------------------------------------
    Roger D. Emerick

/s/ Robert J. Frankenberg                      Director                        August 16, 2001
----------------------------------------
    Robert J. Frankenberg

/s/ Mel Friedman                               Director                        August 16, 2001
----------------------------------------
    Mel Friedman
6

                                INDEX TO EXHIBITS
EXHIBIT
NUMBER                              DOCUMENT
-------                             --------
5.1           Opinion of Morrison & Foerster LLP

   23.1           Consent of Counsel (included in Exhibit 5.1)

   23.2           Consent of Ernst & Young LLP, Independent
                  Auditors

   24.1           Power of Attorney (see Signature Page)