Commentary — Chapter J Design of connections

Chapter J includes the following major changes and additions in this edition of the Specification:

(1) Section J2 clarifies that this Specification takes precedence over AWS Structural Welding Code—Steel, AWS D1.1/D1.1M, when in conflict.
(2) Requirements for use of low-hydrogen electrodes related to minimum size fillet welds have been revised.
(3) Requirements for including increased penetration of fillet and partial-joint-penetration groove welds in the effective throat have been revised.
(4) The strengths for partial-joint-penetration groove-welded column splices and other partial-joint-penetration groove-welded column conditions designed to bear have been combined.
(5) The provisions for directional strength increase for transversely loaded fillet welds have been rewritten and the increase prohibited for use at the ends of rectangular hollow structural sections (HSS).
(6) Section J3.2 clarifies that this Specification takes precedence over the RCSC Specification for Structural Joints Using High-Strength Bolts when in conflict.
(7) Designation of bolt strength groups have been changed from Groups A, B, and C to Groups 120, 150, and 200, reflecting their nominal strengths.
(8) Group 144 (ASTM F3148) bolts and the "combined" installation method have been added.
(9) An alternative tensile strength based on the net tensile area of bolts has been added.
(10) Bearing of through bolts, with plies not in firm contact, on HSS sidewalls has been clarified.

The provisions of Chapter J cover the design of connections not subjected to cyclic loads. Wind and other environmental loads are generally not considered to be cyclic loads. The provisions generally apply to connections other than HSS and box sections. See Chapter K for provisions specific to HSS and box-section connections, and Appendix 3 for fatigue provisions.

C-JCommentary — Chapter J Design of connections