Nail Lateral Design Value (NDS Yield Limit, Face- or Toe-Nailed)
How much sideways load one nail carries between two pieces of wood, face-nailed or toenailed.
Example
You enter
- Nail diameter D (in; 16d common 0.162, 8d common 0.131) 0.162
- Nail length L (in) 3.5
- Side member thickness (in; not used when toenailed) 1.5
- Main member specific gravity G (0.50 DF-L) 0.5
- Side member specific gravity G 0.5
- Toenailed? yes
- Load-duration factor CD (1.6 wind/seismic) 1
You get
- Adjusted for CD and toe-nailing 117 lb (x 0.83 toe-nail)
- P (in) 1.86
Checked against published worked examples from: American Wood Council (AWC).
Details, formula, and sources
ScopeFrom the NDS yield-limit equations: all six yield modes from the wood's specific gravity, the nail's diameter and bending strength, and how far it penetrates. A 16d common toenailed into Douglas fir-larch carries 117 lb, the value AWC's toe-nail design aid tabulates; the same nail face-nailed through 1-1/2 in carries 141 lb, and in both the nail bending (mode IV) governs. The adjusted value applies load duration and the toe-nail factor; the engineer of record governs.
Formula or tableFe = 16,600 G^1.84; Re = Fem/Fes; Rt = p/ls; Rd = 2.2 (D <= 0.17 in) or 10 D + 0.5; Im = D p Fem/Rd; Is = D ls Fes/Rd; II = k1 D ls Fes/Rd; IIIm = k2 D p Fem/((1 + 2Re) Rd); IIIs = k3 D ls Fem/((2 + Re) Rd); IV = (D^2/Rd) sqrt(2 Fem Fyb/(3(1 + Re))); Z = least; toenailed ls = L/3, p = L cos 30 - L/3, Ctn = 0.83; adjusted = Z Ctn CD.
Source and editionANSI/AWC NDS (2018) 12.3.1 yield-limit equations, Table 12.3.3 dowel bearing strength, Appendix I bending yield strengths, and 12.5.4 toe-nail provisions, by name; as tabulated in AWC Design Aid No. 2, Toe-Nail Connections (free at awc.org).
Free accessThe NDS is free to view at awc.org; AWC Design Aid No. 2 is a free PDF; the yield model is also in the USDA Forest Products Laboratory Wood Handbook, chapter 8.
What governsEstimate. AHJ and licensed professional govern.
API field namesd_in, length_in, side_in, gm, gs, toenail, cd, z_adj_lb, p_in
- Reduction term Rd = KD = 2.2 for D <= 0.17 in, 10 D + 0.5 to 0.25 inNDS 2018 Table 12.3.1B
- Fyb 100,000 psi to 0.142 in, 90,000 to 0.177, 80,000 to 0.236, 70,000 to 0.273 unless enteredNDS 2018 Appendix I, Table I1
- Penetration at least 6 D into the main memberNDS 2018 12.3
- Toe-nail side length L/3, penetration L cos 30 - L/3, Ctn = 0.83NDS 2018 12.5.4