1×12

1×12 is a nominal lumber size used in North American construction and woodworking. The designation indicates a board intended to be about one inch thick and twelve inches wide, a broad, flat piece suitable for shelving, trim, paneling, and other non-structural applications.

In practice, the actual dimensions are smaller due to milling. A typical 1×12 measures about 3/4 inch thick and 11 1/4 inches wide (roughly 19 mm by 286 mm). Nominal sizes are traditional labels and vary slightly by species, milling, and finishing, so the stamped dimensions on a board should be consulted when precise sizing is required.

Materials and grades for 1×12 boards vary. They are most commonly produced in softwoods such as pine, spruce, and fir (often referred to as SPF), but hardwood versions are also available. Grades indicate surface quality and the amount of defects like knots; common grades range from select or #1 down to #2 and lower, affecting appearance and price. Availability and price depend on species, moisture content, and region.

Common uses for 1×12 boards include shelving, trim and fascia boards, window sills, and decorative wall paneling. Because of their thickness, they are not typically used as structural framing members, but can serve as decorative or cosmetic elements, or as small, lightweight structural components in non-load-bearing contexts.

Tips for purchase and use include checking the actual dimensions, selecting an appropriate grade for the visible surface, and allowing for acclimation to the installation environment to reduce warping or cupping.