At some point, in the vicinity of 7,000 cycles, the (Syc + Syh) limitation intersects the fatigue curve for carbon and low alloy steel. The allowable stress range must therefore be reduced to fit the fatigue curve for cyclic applications with 7,000 cycles or more:
SE <= F f (SYC + Syh)
Where:
f = cyclic reduction factor, as shown in the accompanying table
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