This web page: http://www.hghouston.com/ss_cwp.html [Broken] states: The web page also shows that fatigue strength can be improved dramatically by cold working. Endurance limit is listed as: 304 annealed = 35 ksi 304 3/4 hard = 92 ksi I'm in the process of designing something that will be subject to fatigue. Cycles will quickly exceed 10^6 cycles, and even 10^8 cycles will come along all to quickly. The part is in axial tension/compression. It will have stress concentrations of about 2 or 3. But the statement makes me wonder... Which material would be best, annealed or cold worked? How can this be quantified?