FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
Trafas Brian M.
   2. Issuer Name and Ticker or Trading Symbol
KLA TENCOR CORP [KLAC] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Executive Vice President
(Last)
(First)
(Middle)
C/O KLA-TENCOR CORPORATION, ONE TECHNOLOGY DRIVE		 3. Date of Earliest Transaction (Month/Day/Year)
08/07/2018
(Street)

MILPITAS, CA 95035		 4. If Amendment, Date Original Filed(Month/Day/Year)
 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)		 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)		 4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)		 5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)		 6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)		 7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 08/07/2018   S   3,859 (1) D $ 118.33 649 D  
Common Stock - Restricted Stock Units (2) 08/07/2018   M   4,300 (3) D $ 0 45,709 (4) D  
Common Stock 08/07/2018   M   4,300 (3) A $ 0 4,949 D  
Common Stock 08/07/2018   F   2,132 (5) D $ 118.16 2,817 D  
Common Stock - Restricted Stock Units (2) 08/07/2018   M   1,837 (6) D $ 0 43,872 (4) D  
Common Stock 08/07/2018   M   1,837 (6) A $ 0 4,654 D  
Common Stock 08/07/2018   F   911 (5) D $ 118.16 3,743 D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number. SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)		 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)		 5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)		 6. Date Exercisable and Expiration Date
(Month/Day/Year)		 7. Title and Amount of Underlying Securities
(Instr. 3 and 4)		 8. Price of Derivative Security
(Instr. 5)		 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)		 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)		 11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Trafas Brian M.
C/O KLA-TENCOR CORPORATION
ONE TECHNOLOGY DRIVE
MILPITAS, CA 95035		       Executive Vice President  

Signatures

 /s/ Teri Little as Attorney-in-Fact for Brian M. Trafas   08/09/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This sale was effected pursuant to the terms of a Rule 10b5-1 trading plan adopted by the Reporting Person on November 9, 2017.
(2) Each restricted stock unit ("RSU") represents a contingent right to receive one share of KLA-Tencor common stock.
(3) On August 7, 2014, in addition to the RSUs granted on that date that were subject only to service-vesting requirements (which RSUs were previously reported on Form 4), the Reporting Person was also granted RSUs covering up to a maximum of 9,187 shares (based on 125% of the target shares of 7,350) of KLA-Tencor common stock, subject to both performance-vesting and service-vesting requirements. On August 31, 2017 the Compensation Committee of KLA-Tencor's Board of Directors determined the level at which the corporate performance goals were attained and, based on the assessment, determined that the number of shares subject to the RSUs is 8,599. On August 7, 2018, the remaining 50% of the shares vested.
(4) Does not include performance-based RSUs, if any, held by the Reporting Person for which an assessment has not yet been made regarding the achievement of the applicable performance goals. Any such holdings will be reported on a Form 4 within two business days of the date such assessment is made.
(5) Pursuant to the terms of the grant, shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding. The fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on August 7, 2018.
(6) On August 7, 2014, the Reporting Person was granted an RSU for 7,350 shares of KLA-Tencor Common Stock. On August 7, 2018, the remaining 25% of those shares vested.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.