Hi tiguy64,
I extract the following values from ASM Metals Handbook:
Material: A316
Hardness: 71-77 HRB
Product Condition: ST
Fatigue strength coefficient: 660 MPa
Fatigue strength exponent: -0.079
Fatigue ductility coefficient: 0.341
Fatigue ductility exponent: -0.453
This values were obtained for R=-1, Longitudinal direction (but AMS does not specify if this is for rotating bending, flexural of push-pull)
Regards,