Abstract: This invention is a device to test fastener heads and thread run-out areas for mechanical strength and detect defects. A fastener head is placed through a hole in a wedge-shaped washer and the shaft put under tension so that the fastener head completely contacts the wedge shaped washer. The stress produced is calculated to be within the elastic limit of the material and produces a stress in the shaft near the fastener head similar to that shown in FIG. 3. If the fastener is defective or is non-conformant to state-of-the-art standards, the fastener will fail when this test device is used. This method allows improved detection of hydrogen embrittened and improper heat treating processes which results in fasteners that will have unsatisfactory mechanical properties.