Astragal

An astragal is a molding profile composed of a convex round section below a flat plane (the fillet). It is often described as a half-round molding, though the term can also refer to a bone in the ankle, which the molding is said to resemble.

In architecture, the astragal is a classical decorative element used in various contexts, most commonly at the top of a column shaft, just below the capital. In this position, it often serves as a transition between the shaft and the capital and is sometimes decorated with bead-and-reel or other ornamental carving. Astragals can also be found as moldings on cornices, door frames, and furniture.

Beyond architecture, the term "astragal" can refer to a small bone in the ankle, specifically the talus bone. This bone connects the tibia and fibula of the lower leg to the foot. The connection to architectural molding stems from the perceived resemblance in shape.

In woodworking and metalworking, astragals can be created using a variety of tools and techniques, including routers, lathes, and molding planes. The precise shape and dimensions of an astragal molding can vary depending on the desired aesthetic and the context in which it is used.