What is an astragal?
An astragal is a narrow, half-round decorative moulding (also called a bead moulding) located at the junction between a column shaft and its capital. It is one of the oldest ornamental elements in classical architecture and is also found on cornices, door frames, and furniture.
The name astragal derives from the Greek word for “vertebra” or “knucklebone”, referring to its characteristic rounded shape. In the classical orders of architecture, the astragal marks the top of the column shaft, just below the transition to the capital. The profile typically consists of a half-round bead (torus), often accompanied by an alternating pattern of beads and reels (bead-and-reel motif).
Application
In classical architecture, the astragal is an integral element of the Ionic and Corinthian orders. It is generally absent from the Doric order. The astragal serves as a visual transition and gives the column a refined, articulated appearance.
Beyond column architecture, the term astragal also refers to:
- Cornices and mouldings — as a decorative profile in facade ornament and interior trim.
- Door frames — an astragal is the narrow strip that covers the gap between the two leaves of a double door, improving both aesthetics and draught-proofing.
- Cabinetry — as an ornamental edge detail on tabletops, cabinets, and drawers.
During restoration of historic buildings, astragal profiles are carefully replicated in stucco, natural stone, or timber to preserve the original architectural character.
Related terms
- Capital
- Column
- Cornice
- Attic base
- Torus
- Architrave
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