Framing Nail Length Progression (12d to 60d)

What happens here

For framing applications, the penny numbering system exhibits 'jumps' after the 10-penny nail, moving to sizes like 12-penny and 16-penny. Despite these numerical jumps, the length continues to increase by 1/4 inch for these specific steps. A significant change occurs with the 20-penny nail; from this point onward, for nails like 30-penny, 40-penny, and the very large 60-penny nail (which measures 6 inches), the length increases by 1/2 inch for each subsequent penny size shown. These larger nails are commonly employed in heavy-duty construction, such as pole barns and certain framing scenarios where greater holding power is required. A 'spike' nail, which is exceptionally large, is also shown as a visual example of very long fasteners, though it typically falls outside the standard penny sizing convention.

Goal: Calculate the length of nails from 12d to 60d and understand their uses.