A heavy-duty, thick-shanked nail driven into asphalt, concrete, or wood to establish a semi-permanent survey point. The head features a distinct indentation in the center, allowing a surveyor to accurately rest the tip of a plumb bob or a prism pole directly on the exact coordinate.
Heard on the job
Drive a PK nail into the edge of the asphalt so we've a solid backsight for tomorrow.
Also heard as
- Parker-Kalon nail
Do not mix it up with
- Spad: A PK nail is driven into the ground or pavement, while a spad is driven into the roof of a mine tunnel to hang a plumb bob.