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 Thermacore® Model 591 


sectional steel doors with windows shown on a dock 

When your project requires a door with an exceptional degree of thermal efficiency, the Thermacore® Model 591 is a proven performer. The Thermacore® steel-polyurethane-steel panel construction provides a thermal barrier that withstands extreme climatic conditions and the most demanding environmental requirements. The Model 591 door's exterior skin is constructed of galvanized steel with a ribbed, textured finish. It is available with a white interior finish and choice of white, industrial brown, tan or gray exterior finish.

Standard max width

35'2" (10,719 mm)

Standard max height

24'1" (7,341 mm)

Panel thickness

1 5/8" (41 mm)


14.86 (2.63 W/Msq)


.07 (.38 Msq/W)

Air infiltration

at 15 mph (24 kmph) .08 cfm/ft2 (1.46 m3/hr/m2)
at 25 mph (40 kmph) .08 cfm/ft2 (1.46 m3/hr/m2)

Thermal break


Exterior steel

.015" (.38 mm) galv.

Exterior surface

Ribbed, textured

Standard springs

10,000 cycle

Wind load

Designs available for usage in high-wind conditions


10 year limited delamination
1 year limited on door
3 year/20,000 cycle limited on door & operator system (when purchased together; on material and workmanship)
20 year limited on high performance fluoropolymer coating option

Exterior color options for 591

color swatch whitecolor swatch almondcolor swatch sandstonecolor swatch brown

High performance fluoropolymer coating (Trinar® or equivalent) finish option available in white, brown and beige. Offers superior performance vs. traditional paint for peeling, cracking, chalking, or fading as well as corrosion resistance.

Actual door color may vary slightly from the digital representation above. Color samples are available by request through your local Overhead Door Distributor.

Interior color

  • White

Window Glazing Options

Additional options

  • Aluminum sash section available up to 24'2" (7,366 mm) wide
  • Insulated glass, tempered glass, polycarbonate, multi-wall polycarbonate, etc.
  • High performance fluoropolymer coating (Trinar® or equivalent)
  • Four-section pass door
  • Knock & Lock® breakaway door system
  • High-usage package
  • Wind load options

  • Electric operator
  • Chain hoist
  • Posi-TensionTM drums
  • Safety bottom fixtures
  • Bottom-sensing edge
  • Flexible jamb, header seal
  • Exhaust ports