OD In Figure show the fatigue curve for a metal. a) If a sample was taken from this material with diameter 5mm and tested on latigue device under constant load 29,4 N far 125.2 mm from the specimen. Find the critical number of cycle in revolution ? b) Find the endurance limit for this material.

Tensile and fully reversed loading fatigue tests were conducted for a certain steelalloy and revealed the tensile strength and endurance limit to be 1200 and 550 MPa,respectively. If a rod of this material supply were subjected to a static stress of 600MPa and fully-reversed oscillating stresses whose total range was 700 MPa. Assuming garber relationship will this rod fail by fatigue failure

I am only interested in part 6-27(a). I see that Bartleby has answered this question before but I have a question regarding the yielding factor of safety. Why is the yielding factor of safety calculated as ( n=Sy/sigma_max), but not as ( n=Sy/Kf*sigma_max)? Since there is stress concentration factor.