form nail

double-headed nail, scaffold nail, form nail

double-headed nail
A nail having two heads, one above the other; the upper head is driven with a hammer, and it is used to withdraw the nail; the lower head bears on the surface into which the nail is driven; used on temporary structures such as scaffolds, formwork, etc.
References in periodicals archive ?
Drive a form nail through the stake and into the form material, holding the top of the form at the desired elevation for the top of the slab.
Form nails are the best choice for nailing dimensioned lumber forms since the double heads make them easy to remove, but using deck screws to connect forms reduces the disruption of forms due to hammering.
Hold the plywood forms against the stakes, adjust to the correct height, and fasten to the stakes using deck screws or form nails installed from the inside of the form through the stake.
Beginning with the bottom riser, nail the riser form in position using form nails driven through the outside of the side forms.