A 25 mm diameter shaft is made of forged steel having ultimate strength in tension as 600 N/mm2. There is a step in the shaft and the theoretical stress concentration factor at step is 2.1 The notch sensitivity factor is 0.84. Determine the endurance limit (MPa) of the shaft if it is subjected to a reverse moment. Take Kb = 0.85 and ka = 0.45 [answer up to 2 decimal places]