OS2 Thermally Broken Products

OS2 Thermally Broken Products

Choose thermally broken steel windows and doors for the best thermal performance available.

Brombal fabricates the world’s first thermally broken steel window, door, and curtain wall system. They are the only manufacturer who has experience working with thermally broken products since their inception and they have completed many successful projects. After years of intense research, the OS2 was born providing narrow sightline, thermally broken window and door systems.

OS2 Thermally Broken Products

OS2 Thermally Broken Windows and Doors are characterized by very narrow, 30 mm (1.2 in) visible sightlines, yet are extremely sturdy and long-lasting. The high thermal efficiency of this product gives a maximum U-value as low as 0.25. This system has excellent design flexibility with four glazing bead profiles, either mechanical or welded corners, and true divided and simulated divided glazing options available. OS2 thermally broken windows and doors are available in a wide variety of configurations.

  • Multipoint locking systems available on all doors and windows
  • Adjustable hinges
  • 1-7/16″ glazing pocket which allows for triple pane glass
  • 4 glazing bead profiles available utilizing a stainless steel clips system
  • Durable powder coat finish available in any of the RAL colors
  • All units engineered to meet all necessary structural designs
  • Tested to meet the most stringent requirements. Includes air, wind, water, and structural


The OS2 has a slender profile while maintaining excellent structural stability. Each unit is designed and engineered specifically to meet the needs of each project. By utilizing different hardware and hinging configurations the OS2 is capable of the most extreme designs.

Galvanized Stainless

Steel is an iron alloy with countless uses. Simple, tough, and perfect for a variety of uses, Steel boasts great tradition and plays an irreplaceable role in the building industry…

Stainless Steel

Stainless steel is an iron alloy containing chromium, nickel, and molybdenum. It was discovered in 1913 by Englishman Harry Brearly after realizing he created a metal which resisted rusting when exposed to atmospheric elements…


Corten steel is a high tensile strength, corrosion resistant steel alloy which contains copper, chromium and phosphorous. The name (Cor-Ten) reflects the special properties of this…


Utilizing the highest quality brass in the fenestration industry, our products are made from 67% copper and 33% Zinc. This ratio is what allows the alloy to acquire a beautiful patina typical of old bronze…


Bi-Metal allows the flexibility of choosing 2 different types of materials to meet interior and exterior design demands. The ability to combine our available metal materials differently on each side…

Metal Wood

Metal-Wood is exactly as it sounds. The ability to combine our available metal materials on one side, and the warmth of wood on the opposite side is now possible. This allows you to carry…


At Brombal, the attention to detail doesn’t stop at the fabrication of the units. The hardware provides the details which complete the look and style of your windows and doors. We offer a variety of handles and styles to choose from ranging from traditional to contemporary. See below for some of the options available.

Please contact us for special hardware requests. We have the ability to replicate and remake custom hardware or utilize a specific hardware of your choice.

Available Configurations


Since all of our units are shipped without glass, it provides great flexibility for the selection of glass based on your specific needs. We work with the largest glass vendors in the country to provide the most energy efficient solution. Some of the vendors we work with are PPG, Cardinal and others.

Please visit our FAQ section for more information on glazing.