An astragal is a piece of hardware that is used on a pair of doors to seal the gap between the doors when they are closed. Astragals are different from a mullion because the astragal is fastened to the door itself. A mullion is attached to the frame and the doors stop against it. Mullions can, however, provide more security than an astragal. In this article we will focus just on door astragals.

Two Types of Astragals

  1. Overlapping
  2. Meeting Stile

Overlapping Astragals

An overlapping astragal is attached to one of the doors in a pair of doors and when the door is closed the astragal will overlap the edge of the other door. This type of astragal requires that the door without the astragal closes first so that the door with the astragal can close and latch properly. The overlapping astragal can be a long, narrow strip of flat metal that is mounted to the face of the active door and overlaps the inactive door. There are also bent astragals that allow space for strike plate.

Overlapping Astragal Piece

Flat Overlapping Astragal

There is also a Z type astragal that is fastened to the edge of the inactive door and is bent so that it covers the gap between the doors.

Z Astragal Overlapping

Overlapping Z Astragal

If the Z astragal is mounted to the edge of the inactive door it will have preps for the strike plate and flushbolts on hollow metal doors. If it is mounted to the active door there are also preps for the lock and strike prep as needed.

The overlapping astragal will always require the correct closing sequence of the doors so that the doors latch and secure properly.

Meeting Stile Astragals

Meeting stile astragals meet in the middle when the doors are closed to seal the gap between the doors. These can be seals that just bump against each other to create the seal, they can have spring adjusted seals that can be readjusted over time if needed, or they can even have magnetic strips that will connect together when closed to ensure a proper seal.

The benefit of meeting stile astragals is that the doors can be opened independently of each other as long as the other hardware on the doors allows for that to happen.


These two types of astragals are used in different circumstances and there are times when one type must be used instead of the other. Consult your Beacon CDL sales representative for direction on what type of astragal will work best for your doors.