Thermacore 591 Series

The 591 Series is one of the best-selling doors in the Thermacore® line, and offers superior thermal efficiency to fit a broad range of applications. The 591 Series exterior skin is constructed of galvanised steel with a ribbed, textured finish. It is available with a white interior finish and choice of white, industrial brown, tan or gray exterior.

When your project requires a sectional door with an exceptional degree of thermal efficiency, the Thermacore® Sectional Steel Door Model 591is 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. 

This 1 5/8” (41 mm) thick, heavy duty door fits a wide range of opening sizes and the spectrum of applications — making it the best-selling door system in the Thermacore® line and one of the most-specified insulated sectional doors in the industry. Boasting an R-value of 14.86 (2.63 W/m2), a U-value of .067 (.380 m2/W), and one of the best air infiltration ratings, the Thermacore® 591 will meet or exceed almost any thermally efficient application requirement.

Thermacore® Model 591

591 Series


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)

.067 (.38 Msq/W)

Air infiltration
at 15 mph (24 kmph) .08 cfm (2.26 Lmp)
at 25 mph (40 kmph) .08 cfm (2.26 Lmp)

Thermal break

Exterior steel
.015″ (.38 mm) galv.

Exterior surface
Ribbed, textured

Standard springs
10,000 cycle

Wind load
Meets ANSI/DASMA 102-1996

10 year limited delamination
1 year limited on door
3 year/20,000 cycle limited on door & operator system
20 year limited on Kynar premium finish option


Exterior Colour

  • white color swatch
  • gray color swatch
  • tan color swatch
  • industrial brown color swatch
    Industrial Brown​​​

Kynar 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.

NOTE: Colours may vary depending on your screen resolution. Please reference actual colour samples prior to purchase.

Interior colour

  • White

Additional Options

  • Thermal glazing
  • Aluminium sash section
  • Kynar premium finish
  • Four-section pass door
  • Knock & Lock® Breakaway Door System
  • High-usage package
  • Wind load options
  • Electric operator
  • Chain hoist
  • Posi-Tension drums
  • Safety bottom fixture
  • Bottom-sensing edge
  • Flexible jamb, header seals
  • Exhaust ports