Yield Limit Equations for Lag Bolts

 

Misc. Comments

1. same equations as for bolts

2. diameter is typically root diameter

3. NDS table L2 shows reduced body and full body  (see NDS 11.3.6)

4 ."...withdrawal design values are applicable for reduced body and full-body diameter lag screws using the nominal lag screw diameter (outside thread diameter for both types)."  source

5. self-tapping lag screws  (pic)

 

 

Penetration

p = L - side member thickness - washer thickness - tapered tip length

dimensions are in NDS table L2

 

 

Dowel Bearing Length l_m

If p ≥ 10D

l_m = p

If p < 10D

l_m = p - tip length

 

NDS tables are for p ≥ 8D

reduction for 4D ≤ p < 8D