Selection Tables

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Lumber to steel plate
Wood member thickness
t
(mm) 		Bolt or
dowel
diameter
(in)
Type 12 (double shear)
Lumber species
D.Fir-L Hem-Fir S-P-F Northern
38 1/2
38 5/8
38 3/4
38 7/8
38 1
89 1/2 7.18(d) 6.91(d) 6.47(a) 5.40(a)
89 5/8 9.10(a) 8.54(a) 7.80(a) 6.50(a)
89 3/4 10.5(a) 9.86(a) 9.01(a) 7.50(a)
89 7/8 11.8(a) 11.1(a) 10.1(a) 8.41(a)
89 1 12.9(a) 12.1(a) 11.1(a) 9.22(a)
140 1/2 8.15(d) 7.83(d) 7.38(d) 6.57(d)
140 5/8 11.7(d) 11.2(d) 10.6(d) 9.50(d)
140 3/4 15.7(d) 15.2(d) 14.3(d) 12.3(a)
140 7/8 19.4(a) 18.2(a) 16.6(a) 13.8(a)
140 1 21.2(a) 19.9(a) 18.2(a) 15.2(a)
191 1/2 9.13(d) 8.74(d) 8.22(d) 7.27(d)
191 5/8 12.9(d) 12.3(d) 11.6(d) 10.3(d)
191 3/4 17.1(d) 16.4(d) 15.5(d) 13.8(d)
191 7/8 21.8(d) 21.0(d) 19.8(d) 17.7(d)
191 1 26.9(d) 25.9(d) 24.5(d) 21.1(a)
241 1/2 10.1(d) 9.64(d) 9.04(d) 7.95(d)
241 5/8 14.0(d) 13.4(d) 12.6(d) 11.2(d)
241 3/4 18.4(d) 17.7(d) 16.6(d) 14.8(d)
241 7/8 23.3(d) 22.4(d) 21.1(d) 18.8(d)
241 1 28.5(d) 27.4(d) 25.9(d) 23.1(d)
292 1/2 11.1(d) 10.6(d) 9.87(d) 8.65(d)
292 5/8 15.2(d) 14.5(d) 13.6(d) 12.0(d)
292 3/4 19.8(d) 18.9(d) 17.8(d) 15.8(d)
292 7/8 24.8(d) 23.8(d) 22.4(d) 19.9(d)
292 1 30.2(d) 29.0(d) 27.3(d) 24.3(d)

Notes:

  1. The connection resistance is the lesser of yielding (provided in this table), splitting (see Table 7.9 in Wood Design Manual 2020), and shear resistances of the wood member. The shear resistance needs to be checked separately by the designer.
  2. The governing failure mode for yielding in each connection configuration is denoted by letter (a)-(g), as per O86 Clause 12.4.4.3.2.
  3. The steel plate thickness is assumed to be 6 mm.
  4. The tabulated lateral resistances are based on removing a 10 mm thick slot to accommodate the 6 mm internal steel plate.
  5. The connection resistance Nr is required to be calculated as follows:
    • Nr = N'r nF (KD KSF KT) for mode (a),
    • Nr = N'r nF for mode (c),
    • Nr = N'r nF (KDy KSF KT) for mode (d) or (g).

    nF is the number of fasteners in the connection. Modification factors are provided in Section 7.4 of the Wood Design Manual 2020. For untreated wood members under standard-term loading and dry service conditions, the modification factors are 1.0.

  6. Tabulated values are based on No.1/ No.2 grade for dimension lumber (38 to 102 mm in smaller dimension) and No.2 grade for timbers (114 or more in smaller dimension).
  7. Tabulated values are based on ASTM A307 grade steel bolts or dowels, and ASTM A36/A36M grade steel plate. The resistance of steel plate needs to be checked separately.
  8. A single steel splice plate is not permitted to be used when the distance between the first and last bolts in a row exceeds 125 mm.