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                                                  Filed by Komag, Incorporated
                                                  Pursuant to Rule 425 under the
                                                  Securities Act of 1933, and
                                                  deemed filed Pursuant to Rule
                                                  14a-12 under the Securities
                                                  and Exchange Act of 1934.
                                                  Subject Company:
                                                  HMT Technology Corp.
                                                  Commission File No. 000-27586

                             KOMAG, INCORPORATED
            E-MAIL COMMUNICATION CONCERNING TRANSACTION INVOLVING
                 KOMAG, INCORPORATED AND HMT TECHNOLOGY CORP

Communication to Komag Employees


WHAT ARE THE BENEFITS OF THIS MERGER?

The data storage industry has profoundly changed over the last 3 years. Critical
for companies today is the ability to meet time-to-market demands at the lowest
possible cost. The merger is a vital strategic move that creates the most
compelling value proposition in the media world.

The technology groups of the two companies, when combined, will provide the best
possible technology to the industry. We expect to be in a position to qualify
for every major new program at our customers. Not only will the combined company
be in a more financially viable position to serve the independent drive makers,
the new company will also be in a better position to be the vendor of choice for
the vertically-integrated drive-makers.

WHAT ARE THE TERMS OF THE AGREEMENT?

Each company's board of directors unanimously approved the terms of a
definitive merger agreement. Under the terms of the definitive merger
agreement, each issued and outstanding share of HMT stock will be converted
into 0.9094 shares of Komag stock. The companies have agreed to merge in a
tax-free transaction to be accounted for under purchase accounting.

WHAT IS GOING TO HAPPEN?

A joint transition team, led by T.H. Tan, President & CEO of Komag, and Ron
Buschur, President and COO of HMT, will develop a plan for merging and
streamlining the management of both companies after the "close". The deal is
expected to be completed during the third calendar quarter. Between now and the
"close", both companies will operate as they do today.
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HOW WILL EMPLOYEES BE AFFECTED BY THE MERGER?


Even though this is an important strategic step for both companies, people's
job's are ultimately affected and some jobs will be eliminated as the companies
combine. As we consolidate, ALL EMPLOYEES WILL BE TREATED EQUALLY AND FAIRLY.
Plans will be communicated to all employees as quickly as possible. Change of
this nature can be unsettling to everyone involved. Both Komag and HMT are
committed to making this the most positive, productive transition for all
concerned.

In the big picture, the data storage industry has changed, but it continues to
grow and data storage does matter! By combining Komag and HMT, the resulting
company will have proactively and methodically positioned itself to be a leading
player in the new media frontier.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements within the meaning of the
Safe Harbor Provisions of the Private Securities Litigation Reform Act of 1995.
These statements regarding, among other things, the expected cost structure and
cash flow of the combined company, represent the companies' reasonable judgments
with respect to future events and are subject to risks and uncertainties that
could cause actual results to differ materially. Such factors include, but are
not limited to, failure of the transaction to close due to regulatory or lender,
shareholder or regulatory approvals, the risk that Komag and HMT will not
successfully integrate their businesses or that the cost of such integration
will be greater than anticipated, failure of the combined company to retain and
hire key executives, technical personnel and other employees, material adverse
changes in economic and competitive conditions in the markets served by the
companies, material adverse changes in the business and financial condition of
either or both companies and their customers, uncertainties concerning
technological changes and future product performance, and substantial delay in
the expected closing of the transaction.

WHERE YOU CAN FIND ADDITIONAL INFORMATION

Investors and security holders of both HMT and Komag are advised to read the
joint proxy statement/prospectus regarding the business transaction referenced
in the foregoing information, when it becomes available, because it will contain
important information. HMT and Komag expect to mail a joint proxy
statement/prospectus about the transaction to their respective stockholders.
Such joint proxy statement/prospectus will be filed with the Securities and
Exchange Commission by both companies. Investors and security holders may obtain
a free copy of the joint proxy statement/prospectus (when available) and other
documents filed by the companies at the Securities and Exchange Commission's web
site at http://www.sec.gov. The joint proxy statement/prospectus and such other
documents may also be obtained from HMT or Komag by directing such requests to
the respective investor relations contacts listed below.

HMT and its officers and directors may be deemed to be participants in the
solicitation of proxies from HMT 's stockholders with respect to the proposed
transaction. Information regarding such officers and directors is included in
HMT's proxy statement for its annual meeting of stockholders filed with the
Securities and Exchange Commission on June 28, 1999. This document is available
free of charge at the Securities and Exchange Commission's web site at
http://www.sec.gov and from the HMT investor relations' contacts listed below.

Komag and its officers and directors may be deemed to be participants in the
solicitation of proxies from Komag's stockholders with respect to the proposed
transaction. Information regarding such officers and directors is included in
Komag's proxy statement for its annual meeting of stockholders filed with the
Securities and Exchange Commission on April 10, 2000. This document is available
free of charge at the Securities and Exchange Commission's Web site at
http://www.sec.gov and from the Komag investor relations' contacts listed below.

Contacts:

For Komag:

Ted Siegler at (408) 576-2209 or
Russell Lemelin at (408) 576-2485
E-mail communications: ir_web@komag.com

For HMT:

Peter Norris, (510) 490-3100
Investor Relations, (510) 683-6000