Door Details

Image of door specificationsKarpen Steel fabricates Seamless Edge, Vertically Steel Stiffened Doors, 1¾”, and 1⅜” up to 2″ thick as specified, as well as 1¾” and 1⅜” thick polystyrene core doors. Thicker doors, steel stiffened, over 2″ are also available.


  • 18- 16- or 14-gauge face sheets of commercial grade Cold Rolled Steel.
  • 18- 16- or 14-gauge face sheets of commercial grade A60 Galvannealed.
  • 12-gauge face sheets. 12-gauge Door Specifications


  • Standard Core:
    • Doors shall have continuous vertical interlocking steel stiffeners of 20-gauge and shall be spaced no further than 8″ on center.
    • Doors shall be filled with mineral rock wool insulation.
  • Alternate Core for 1¾” thick doors:
    • Polystyrene Core with a density of 1 lb/cubic foot.
    • Face Sheets for Polystyrene Core: A60 Galvanneal


  • Top and bottom of doors shall be reinforced with continuous 16-gauge steel channels, spot welded to both sides of doors.
  • Hinge reinforcements shall be 11-gauge steel angle,
    12″ long
  • Cylindrical lock reinforcement shall be 16-gauge with 11-gauge thread depth. Other lock and closer reinforcements shall be 12-gauge.
  • Doors shall be reinforced for all surface type hardware. Drilling and tapping of surface hardware to be done in the field by the erector.
  • Edges of door shall be continuously seam welded, ground, and filled to ensure a smooth finish.


  • Doors shall be thoroughly cleaned after assembly and given a prime coat of rust inhibiting paint. The primer shall be air dried. Low gloss oil base trim paints (max gloss 25) are recommended as a finish paint.


  • ¾” standard. Other undercuts as specified.

Hinge Backset: (1¾” thick doors)

  • ¼” standard. 3⁄16″ or ⅛” available.


  • ⅛” in 2″ standard. (18, 16 and 14 gauge doors)
    12 gauge doors: Square Edge only.


  • Flat 14-gauge astragals are provided with pairs of doors as needed and are shipped loose for field mounting. Flat Astragal Drawing
  • “Z” Astragals are available with or without hardware preps for an additional charge. These can be ordered for existing doors or for use with doors by Karpen Steel. “Z” Astragal Drawing

Size Limitations

Largest single door available up to 1¾” thick without face seams are shown below. Doors are available with vertical face seams up to 8′ in total width.

18CRS or A60 Galvanneal 4′-7″ x 10′-0″
16 or 14CRS or A60 Galvanneal4′-7″ x 10′-0″
12HRPO or Galvanneal4′-7″ x 10′-0″

Door Design Drawings

Drawing showing various options for vision lite kit and louver placements.

INTERNAL DOOR DETAIL-Vertically Steel Stiffened

Vertically steel stiffened doors with interlocking rib design. These ribs are used in 1¾” thick and 1⅜” thick steel stiffened doors. Slightly different ribs and high hats are used in other door thicknesses. Edges are available as either square or beveled, with beveled being standard unless otherwise specified.

INTERNAL DOOR DETAIL-Polystyrene Core Detail

Polystyrene core door details for 1⅜” thick and 1¾” thick doors.