Slip-Critical Bolt Design Strength (AISC 360 J3.8)
Where slip cannot be tolerated - oversized holes, fatigue, load reversal - the joint is governed by friction, not shear: Rn = mu Du hf Tb ns with mu 0.30 (Class A) or 0.50 (Class B blast-cleaned), Du 1.13, and the Table J3.1 pretension. A 3/4 in A325 on a Class A surface resists 9.49 kip per bolt (6.33 ASD); go Class B in double shear and one bolt jumps 3.3x to 31.6 kip - surface prep and a second plane are the levers. The strength-level bolt-shear-bearing check must also pass. A design aid, not the engineer of record's stamped design.
Formula and source
Rn_bolt = mu Du hf Tb ns; ASD = Rn/1.50, LRFD = 1.00 Rn (standard holes); totals = n x per-bolt.
The AISC 360-22 J3.8 slip-critical connection resistance with the Class A/B slip coefficients, Du = 1.13, the Table J3.1 minimum pretension, and the standard-hole phi = 1.00 / Omega = 1.50, by name.
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