This document specifies the conditions for conducting axial, constant-amplitude, force-controlled, fatigue tests at ambient, elevated, and low temperature on metallic specimens, without deliberately introduced stress concentrations. The object of testing while employing this document is to provide fatigue information, 

such as the relation between applied stress and number of cycles to failure for a given material condition, such as hardness and microstructure, at various stress ratios. While the form, preparation and testing of specimens of circular and rectangular cross-section are described, component testing and other specialized forms of testing are not included in this document. NOTE 1 Fatigue tests on notched specimens are not covered by this document since the shape and size of notched 

test pieces have not been standardized. However, fatigue-test procedures described in this document can be applied to fatigue tests of such notched specimens.

 NOTE 2 Throughout this document, the engineering stress is employed. Engineering stress is defined as the quotient of the axially applied force to the cross-sectional area of the test specimen, S = Force/Area, at the test temperature.