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Lesson 25: Spacing, End, and Edge Distances: Geometry Factor CΔ

Nominal design values for bolts, lag screws, and other connectors (such as shear plates, split rings, rivets, and drift bolts and pins) require that specific end and edge distances are maintained. The NDS provides two edge and end distance requirement levels: one for full design values, and another for minimum distance permitted. When the actual distances used are less than those required for full design values but greater than the minimum permitted, the geometry factor can be applied to account for this. Three geometry factors may be calculated to adjust for:

  • Edge distance
  • End distance
  • Spacing fasteners in a row

The smallest factor for any fastener in a group is applied to all fasteners in that group. The minimum edge and end distances, spacing, and geometry factors are the same for lag screws and bolts, having equal shank diameters.