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Figure 21 delineates a series of regions for various ratios of applied stress to yield strength of the material, AS/YS. Once the ratio K~occ-EHdYS has been measured, the maximum value of the AS/YS ratio can be identified for a given bolt diameter. The stress AS is the tensile stress and must be correlated to the applied torque from the torque-tension measurements to calculate the maximum applied installation torque. If a higher stress results because of bending or the scatter in the torque-tension correlation, failure will occur, and that will result in a brittle fracture. This design criterion is considered to be "safe life" as compared to "fail safe."