Reference: thread507-436818
I get the same result as OP for 1/4" lag screw capacity. The discrepancy (with NDS) appears to be how Fe is calculated. Since Dr = 0.173 < .25, Fe=16600G^1.84=4637 psi (see footnote 2 of NDS Table 12.3.3), for G=0.50.
It appears that 2018 NDS Table 12J and the...