Exhibit 99.1 FOR IMMEDIATE RELEASE Chicago Rivet & Machine Co. Reports 2004 First Quarter Earnings Naperville, IL, May 3, 2004 --- Chicago Rivet & Machine Co. (AMEX, symbol CVR) reported net income for the first quarter of 2004. Results are summarized below: CHICAGO RIVET & MACHINE CO. SUMMARY OF CONSOLIDATED RESULTS OF OPERATIONS FOR THE THREE MONTHS ENDED MARCH 31 <Table> <Caption> 2004 2003 ---- ---- Net sales and lease revenue.................. $ 10,168,964 $ 10,236,463 Income before taxes.......................... 442,988 709,241 Net income................................... 290,988 465,241 Net income per share......................... .30 .48 Average shares outstanding................... 966,132 966,132 </Table> - -------------------------------------------------------------------------------- (All figures subject to year-end audit) Contacts: Kimberly A. Kirhofer or John C. Osterman Chicago Rivet & Machine Co. (630) 357-8500