SEC Filing Html Data



SCHEDULE 13G

Amendment No. 2
CompX International Incorporated
Class A common stock
Cusip # 20563P101


Cusip # 20563P101
Item 1:	Reporting Person - Fidelity International Limited
Item 4:	Bermuda
Item 5:	66,000
Item 6:	0
Item 7:	66,000
Item 8:	0
Item 9:	860,766
Item 11:	14.003%
Item 12:	    HC


Cusip # 20563P101
Item 1:	Reporting Person - Edward C. Johnson 3d
Item 4:	United States of America
Item 5:	0
Item 6:	0
Item 7:	860,766
Item 8:	0
Item 9:	860,766
Item 11:	14.003%
Item 12:	IN


Cusip # 20563P101
Item 1:	Reporting Person - Abigail P. Johnson
Item 4:	United States of America
Item 5:	0
Item 6:	0
Item 7:	860,766
Item 8:	0
Item 9:	860,766
Item 11:	14.003%
Item 12:	IN



SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(c)

Item 1(a).	Name of Issuer:

		CompX International Incorporated

Item 1(b).	Name of Issuer's Principal Executive Offices:

		200 Old Mill Road,
		Mauldin, SC 29662

Item 2(a).	Name of Person Filing:

		Fidelity International Limited

Item 2(b).	Address or Principal Business Office or, if None,
Residence:

		Pembroke Hall, 42 Crowlane
		Hamilton, Bermuda

Item 2(c).	Citizenship:

		Not applicable

Item 2(d).	Title of Class of Securities:

		Class A common stock

Item 2(e).	CUSIP Number:

		20563P101

Item 3.	This statement is filed pursuant to Rule 13d-1(c).

		Not applicable

Item 4.	Ownership

	(a)	Amount Beneficially Owned:
	860,766

	(b)	Percent of Class:
	14.003%

	(c)	Number of shares as to which such person has:

	(i)	sole power to vote or to direct the vote:
	66,000

	(ii)	shared power to vote or to direct the vote:
	0

	(iii)	sole power to dispose or to direct the
disposition of:	66,000

	(iv)	shared power to dispose or to direct the
disposition of:	0



Item 5.	Ownership of Five Percent or Less of a Common Stock.

	Not applicable.

Item 6.	Ownership of More than Five Percent on Behalf of Another
Person.

	Various persons have the right to receive or the
power to direct the receipt of dividends from, or
the proceeds from the sale of, the Class A common
stock of CompX International Incorporated.  No one
person's interest in the Class A common stock of
CompX International Incorporated is more than five
percent of the total outstanding Class A common
stock.

Item 7.	Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on By the Parent
Holding Company.

	See attached Exhibit(s) A, B, and C.

Item 8.	Identification and Classification of Members of the
Group.

	Not Applicable. See attached Exhibit A.

Item 9.	Notice of Dissolution of Group.

	Not applicable.

Item 10.	Certification.

	By signing below I certify that, to the best of my
knowledge and belief, the securities referred to
above were not acquired and are not held for the
purpose of or with the effect of changing or
influencing the control of the issuer of the
securities and were not acquired and are not held in
connection with or as a participant in any
transaction having that purpose or effect.

Signature

	After reasonable inquiry and to the best of my
knowledge and belief, I certify that the information
set forth in this Schedule 13G in connection with
Fidelity International Limited's beneficial
ownership of the Class A common stock of CompX
International Incorporated at November 4, 1999 is
true, complete and correct.


	November 11, 1999
Date




Signature



	Eric D. Roiter
	Duly authorized under
Power of Attorney
	dated December 30, 1997,
by and on behalf
	of Fidelity International
Limited and it
	direct and indirect
subsidiaries




SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(c)

	Pursuant to the instructions in Item 7 of Schedule 13G,
Fidelity Management & Research Company ("Fidelity"), 82
Devonshire Street, Boston, Massachusetts 02109, a wholly-owned
subsidiary of FMR Corp. and an investment adviser registered
under Section 203 of the Investment Advisers Act of 1940, is the
beneficial owner of 586,366 shares or 9.539% of the Class A
common stock outstanding of CompX International Incorporated
("the Company") as a result of acting as investment adviser to
various investment companies (the "funds") registered under
Section 8 of the Investment Company Act of 1940.

	Edward C. Johnson 3d, FMR Corp., through its control of
Fidelity, and the funds collectively each has sole power to
dispose of the 586,366 shares owned by the Funds.

	Neither FMR Corp. nor Edward C. Johnson 3d, Chairman of FMR
Corp., has the sole power to vote or direct the voting of the
shares owned directly by the funds, which power resides with the
funds' Boards of Trustees.  Fidelity carries out the voting of
the shares under written guidelines established by the funds'
Boards of Trustees.

	Fidelity Management Trust Company, 82 Devonshire Street,
Boston, Massachusetts 02109, a wholly-owned subsidiary of FMR
Corp. and a bank as defined in Section 3(a)(6) of the Securities
Exchange Act of 1934, is the beneficial owner of 208,400 shares
or 3.390% of the Class A common stock outstanding of the Company
as a result of its serving as investment manager of the
institutional account(s).

	Edward C. Johnson 3d and FMR Corp., through its control of
Fidelity Management Trust Company, each has sole dispositive
power over 208,400 shares and sole power to vote or to direct the
voting of 208,400 shares.

	Strategic Advisers, Inc., 82 Devonshire Street, Boston, MA
02109, a wholly-owned subsidiary of FMR Corp. and an investment
adviser registered under Section 203 of the Investment Advisers
Act of 1940, provides investment advisory services to
individuals. It does not have sole power to vote or direct the
voting of shares of certain securities held for clients and has
sole dispositive power over such securities. As such, FMR Corp.'s
beneficial ownership may include shares beneficially owned
through Strategic Advisers, Inc.

	Members of the Edward C. Johnson 3d family are the
predominant owners of Class B shares of common stock of FMR
Corp., representing approximately 49% of the voting power of FMR
Corp.  Mr. Johnson 3d owns 12.0% and Abigail Johnson owns 24.5%
of the aggregate outstanding voting stock of FMR Corp.  Mr.
Johnson 3d is Chairman of FMR Corp. and Abigail P. Johnson is a
Director of FMR Corp.  The Johnson family group and all other
Class B shareholders have entered into a shareholders' voting
agreement under which all Class B shares will be voted in
accordance with the majority vote of Class B shares.
Accordingly, through their ownership of voting common stock and
the execution of the shareholders' voting agreement, members of
the Johnson family may be deemed, under the Investment Company
Act of 1940, to form a controlling group with respect to FMR
Corp.

	Fidelity International Limited, Pembroke Hall, 42 Crowlane,
Hamilton, Bermuda, and various foreign-based subsidiaries provide
investment advisory and management services to a number of non-
U.S. investment companies and certain institutional investors.
Fidelity International Limited is the beneficial owner of 66,000
shares or 1.073% of the Class A common stock outstanding of the
Company. Additional information with respect to the beneficial
ownership of Fidelity International Limited is shown on Exhibit
B.

	FMR Corp. and Fidelity International Limited are of the view
that they are not acting as a "group" for purposes of Section
13(d) under the Securities Exchange Act of 1934 (the "1934 Act")
and that they are not otherwise required to attribute to each
other the "beneficial ownership" of securities "beneficially
owned" by the other corporation within the meaning of Rule 13d-3
promulgated under the 1934 Act.  Therefore, they are of the view
that the shares held by the other corporation need not be
aggregated for purposes of Section 13(d).  However, Fidelity
International Limited is making this filing on a voluntary basis
as if all of the shares are beneficially owned by FMR Corp. and
Fidelity International Limited on a joint basis.


EXHIBIT to SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(c)

	Pursuant to instructions in Item 7 of Schedule 13G, this
Exhibit has been prepared to identify Fidelity International
Limited, Pembroke Hall, 42 Crow Lane, Hamilton, Bermuda, a
Bermudan joint stock company incorporated for an unlimited
duration by private act of the Bermuda Legislature (FIL) and an
investment adviser to various investment companies (the
"International Funds") and certain institutional investors, as a
beneficial owner of the 66,000 shares or 1.073% of the Class A
common stock outstanding of CompX International Incorporated.

	Prior to June 30, 1980, FIL was a majority-owned subsidiary
of Fidelity Management & Research Company (Fidelity), a wholly-
owned subsidiary of FMR Corp.  On that date, the shares of FIL
held by Fidelity were distributed, as a dividend,  to the
shareholders of FMR Corp.  FIL currently operates as an entity
independent of FMR Corp. and Fidelity.  The International Funds
and FIL's other clients, with the exception of Fidelity and an
affiliated company of Fidelity, are non-U.S. entities.

	A partnership controlled by Edward C. Johnson 3d and members
of his family owns shares of FIL voting stock with the right to
cast approximately 39.89% of the total votes which may be cast by
all holders of FIL voting stock.  Mr. Johnson 3d is Chairman of
FMR Corp. and FIL.  FMR Corp. and FIL are separate and
independent corporate entities, and their Boards of Directors are
generally composed of different individuals.  Other than when one
serves as a sub adviser to the other, their investment decisions
are made independently, and their clients are generally different
organizations.

	FMR Corp. and Fidelity International Limited are of the view
that they are not acting as a "group" for purposes of Section
13(d) under the Securities Exchange Act of 1934 (the "1934 Act")
and that they are not otherwise required to attribute to each
other the "beneficial ownership" of securities "beneficially
owned" by the other corporation within the meaning of Rule 13d-3
promulgated under the 1934 Act.  Therefore, they are of the view
that the shares held by the other corporation need not be
aggregated for purposes of Section 13(d).  However, Fidelity
International Limited is making this filing on a voluntary basis
as if all of the shares are beneficially owned by FMR Corp. and
Fidelity International Limited on a joint basis.

	FIL has sole dispositive power over 66,000 shares owned by
the International Funds. FIL has sole power to vote or direct the
voting of 66,000 shares of Class A common stock held by the
International Funds as reported above.



SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(c)
RULE 13d-1(f)(1)  AGREEMENT

	The undersigned persons, on November 11, 1999, agree and
consent to the joint filing on their behalf of this Schedule 13G
in connection with their beneficial ownership of the Class A
common stock of CompX International Incorporated at November 4,
1999.

Fidelity International Limited

By   /s/Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of
Attorney
	dated December 30, 1997, by and on
behalf
	of Fidelity International Limited
and its direct
and indirect subsidiaries.

Edward C. Johnson 3d

By   /s/Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of
Attorney
	dated December 30, 1997, by and on
behalf
	of Edward C. Johnson 3d.

Abigail P. Johnson

By   /s/Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of
Attorney
	dated December 30, 1997, by and on
behalf
	of Abigail P. Johnson.

FMR Corp.

By   /s/Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of
Attorney
	dated December 30, 1997, by and on
behalf
	of FMR Corp. and its direct and
indirect
	subsidiaries.