This International Standard specifies the conditions for carrying out axial load fatigue tests on threaded fasteners, as well as recommendations for the evalu-ation of the results.
Unless otherwise agreed, the tests are of the fluctu-ating tension type and are carried out at room tem-perature, the loading applied being centric along the longitudinal axis of the fastener. The influence of the compliance of clamped parts on the strain of the fastener is not taken into account.
This method allows determination of the fatigue strength of threaded fasteners.
The test results can be influenced by the test condi-tions. For this reason, minimum requirements are specified to reduce this effect. In addition, calibration and centring control methods for the testing appar-atus are included.
BS 7774:1994 history
1994BS 7774:1994 Threaded fasteners. Axial load fatigue testing. Test methods and evaluation of results