Two Washington investors reported yesterday that they have purchased about 9 percent of Easco Corp., a Baltimore-based tool maker and metals producer, for $9 million.

Steven M. Rales and Mitchell P. Rales, the sole partners in Equity Group Holdings, bought 653,700 common shares of Easco, or 9.2 percent of the company's outstanding shares.

Equity Group might seek control of Easco, according to a filing with the Securities and Exchange Commission.

The SEC filing said that Equity purchased the shares to acquire a significant equity position in Easco and, "depending upon Equity's continuing evaluation of Easco's business and prospects and upon future developments Equity may consider seeking control of Easco."

The Easco shares were purchased between Sept. 10 and Nov. 29 in open-market transactions for prices ranging from $12.50 to $14.25 a share, according to the SEC filing.

Easco recently reported operating losses for the third quarter and nine months ending Sept. 30. In its third quarter, the company reported a net loss of $5.9 million (87 cents a share) compared with net income of $2.8 million (42 cents) in the same period of 1983.

For the nine months, Easco reeported a net loss of $6.1 million (90 cents) compared with profits of $7.7 million ($1.27) in the same period last year.

"The losses reflected reductions in hand-tool production rates, ongoing expenses associated with the technological-improvement program and sizable costs related to remedial action taken by new management to restructure and strengthen the entire hand-tool group," Easco Chairman Richard P. Sullivan said in a quarterly report.