Lateral strength is largely a function of a nail’s diameter and the density of the type of wood into which the nail is driven. For example, 10d and 12d nails have the same diameter and the same lateral strength in each type of wood. Common nails are stronger than box nails because of their greater diameter (below).
When substituting box for common nails, calculate the nail size needed using the conversion ratios shown below.
Figure: Conversion Ratio for Common to Box Nails
S-P-F lumber assumed.
Do not substitute a common nail that’s specified on the plans for an equal number of box nails. Instead, multiply the specified number of common nails by the conversion ratio shown in the chart and round up to find the equivalent number of box nails.