In this study, the determination of the opening mode stress intensity factor by using strain gage methods is investigated both experimentally and analytically. The results are compared with the finite element solution. In the experimental program, cracks are opened at the tip of crack starter slot on the standard compact tension test specimens by using Electrical Discharge Machining (EDM) and Wiring Discharge Machining (WDM). Strain gage data from the crack tip region are used to calculate stress intensity factors with some limitations. Copyright © 1996 Elsevier Science Ltd.