This table catalogs structural and mechanical bolt specifications, indexed by specification grade (PK) and nominal diameter (SK), with tensile and yield strengths, proof load, tensile stress area, minimum pretension, and shear and tensile nominal stresses for both X-thread-excluded and N-thread-included shear planes. The dominant engineering decision the data supports is selecting a bolt grade and size that delivers a target preload high enough to keep the joint clamped under service load while staying below proof strength during installation.

The mechanics behind these values come from Shigley Chapter 8: a tension joint is modeled as a bolt spring in parallel with a member spring, so the external load P splits into a bolt share C·P and a member share (1−C)·P, where C = k_b / (k_b + k_m) is the joint stiffness constant (Shigley §8-7). Installation torque is tied to preload by T = K · F_i · d (Shigley §8-8, Eq. 8-27) with K from the surface-condition factors in Table 8-15 (0.30 black finish down to 0.09 with anti-friction nuts), and recommended preload is F_i = 0.75·A_t·S_p for reused connections or 0.90·A_t·S_p for permanent ones (Shigley §8-9, Eqs. 8-31 and 8-32).

The designer workflow is to pick a specification (for example A325 or property class 8.8) at a candidate diameter, read S_p and A_t from this table, compute F_i at the 0.75 or 0.90 fraction, then convert F_i to assembly torque using K from the bolt's surface condition. The same S_p and A_t feed the static yielding factor n_p = S_p·A_t / (C·P + F_i) and the joint separation factor n_0 = F_i / [P·(1−C)] per Shigley Equations 8-29 and 8-30.

Caveats: under fluctuating external load, the static proof check is not sufficient, and fatigue safety must be evaluated with the rolled-thread fatigue stress concentration factor K_f and corrected endurance strength S_e (Shigley Table 8-16 and Table 8-17), then a Goodman or Gerber criterion applied (per Shigley Section 8-11), with Goodman conservative and Gerber closer to test data. Gasketed joints reduce member stiffness sharply and require the gasket-specific stiffness treatment in Shigley Section 8-10, and elevated-temperature service (hot-bolting) relaxes preload over time so the F_i values in this table cannot be assumed retained without retorque procedures.