PARTS OF A COMMERCIAL DOOR


  1. Window Lite
    Glazed section with various types of glass or clear acrylic to allow for light and visibility.
  2. Sections
    Steel panels reinforced with stiles interconnected with hinges and rollers.
  3. Bottom Bracket
    A structured support that provides for attachment of lifting cables.
  4. Cable Drum
    Grooved drums on the torsion spring shaft that lifting cables wind around when the door opens.
  5. Torsion Springs
    Provides the means to raise and lower the door via cable winding on drums.
  6. Extension
    Extends along both horizontal tracks.
  7. Rear Hanger Track
  8. Track
    Provides a guide for section to raise or lower door.
  • Track Types: Standard, Low Headroom, High Lift, Vertical Lift
  • Track Components:
  • Vertical Track: on either side of opening.
  • Horizontal Track: attached to ceiling.
  • Radius: curved track.


  • Standard Heights
    • 7 feet high - Typically 4 sections high
    • 8 feet high - Typically 5 sections high




    Gauge = Steel Thickness
    • A lower number is better. 24 gauge is thicker than 25 gauge.
    Garage Door - Diagram