Table K2.1A: Limits of Applicability of Table K2.1

HSS wall slenderness: $D/t \leq 50$ for T-connections under branch plate axial load or bending $D/t \leq 40$ for cross-connections under branch plate axial load or bending Width ratio: $0.2 < B_{b}/D \leq 1.0$ for transverse branch plate connections Material strength: $F_{y} \leq 52$ ksi (360 MPa) Ductility: $F_{y}/F_{u} \leq 0.8$ Note: ASTM A500/A500M Grade C is acceptable.

(a) When the punching load, $P_{r} \sin \theta$ , in a branch member is equilibrated by beam shear in the chord member, the connection shall be classified as a T-connection when the branch is perpendicular to the chord, and classified as a Y-connection otherwise.
(b) When the punching load, $P_{r} \sin \theta$ , in a branch member is essentially equilibrated (within 20%) by loads in other branch member(s) on the same side of the connection, the connection shall be classified as a K-connection. The relevant gap is between the primary branch members whose loads equilibrate.

User Note: A K-connection with one branch perpendicular to the chord is often called an N-connection.

(c) When the punching load, $P_{r} \sin \theta$ , is transmitted through the chord member and is equilibrated by branch member(s) on the opposite side, the connection shall be classified as a cross-connection.
(d) When a connection has more than two primary branch members or branch members in more than one plane, the connection shall be classified as a general or multiplanar connection.

User Note: Limit states are not defined for general or multiplanar HSS-to-HSS truss connections.

When branch members transmit part of their load as K-connections and part of their load as T-, Y-, or cross-connections, the adequacy of the connections shall be determined by interpolation on the proportion of the available strength of each in total.

For trusses that are made with HSS that are connected by welding branch members to chord members, eccentricities within the limits of applicability are permitted without consideration of the resulting moments for the design of the connection.