cat's-paw

A cat's-paw is a short prying tool, typically 6 to 10 inches long, with a handle set at roughly 90 degrees to a flat blade. The working end features a shallow V-shaped notch designed to grip a nail head. The offset angle between handle and blade gives the user mechanical advantage when applying downward pressure to extract nails from wood or other materials.

The tool works by sliding the notched blade under a nail head, then pivoting the handle downward. The angle transfers the operator's force into upward leverage on the nail. Most cat's-paws are forged steel with a hardened blade edge to withstand repeated impact and bending stress. The handle may be metal, wood, or wrapped steel; good ones have a slight curve or knurled grip to prevent slipping when wet or sweaty.

Larger versions, sometimes called wrecking bars or pry bars, reach 12 to 20 inches and handle bigger nails and more stubborn extraction work. Smaller nail pullers and nail sets exist for finish carpentry where minimal damage to surrounding wood is critical. The cat's-paw sits between these specialists: rugged enough for rough framing, small enough to fit into tight spots where larger bars cannot go.

The notch works best on nail heads between roughly 2 and 16 penny sizes. Very large industrial nails or very small finish nails slip out or require different tools. The V-shaped notch also marks the wood slightly during extraction, which is acceptable on rough work but problematic in visible surfaces. On delicate work, carpenters often slip a thin wood block under the blade to distribute the fulcrum load and reduce surface damage.

The name likely derives from the tool's resemblance to a cat's curved paw, though some sources suggest it refers to the clawing action required to extract stubborn nails. It has been a standard in carpentry and general construction for well over a century, and variants appear under different names in different regions and trades, though the form and function remain consistent.