At Optimum, we take pride in creating custom steel windows that preserve the character of the past while meeting the demands of today.
Precision matters.
So does the story behind every structure.
That’s why our Flex 6500SB Series is built with the strength and subtlety that heritage buildings deserve.
Built for the Past, Engineered for the Future
We don’t just manufacture windows—we protect legacies.
The Flex Series was created for the restoration of landmark and historic buildings that require a precise visual match and modern performance.
You get both.
No compromises.
| Feature | Flex Series Advantage |
|---|---|
| Frame Construction | Fully welded cold-rolled steel |
| Thermal Break | Yes – energy efficient for historic retrofits |
| Finish | Powder-coated, meets AAMA 2604 |
| Glazing Thickness | 1” to 1 5/8” |
| Hardware Options | Single-point, multi-point, and custom finishes |
| Available Materials | Galvanized Steel, Stainless, Bronze, COR-TEN |
Why Cold-Rolled Steel Works So Well for Historic Restorations
Cold-rolled steel is slim, durable, and clean-lined, which makes it the ideal material for replicating classic architectural steel windows from the early 20th century.
It blends into historic facades like it was always there.
But it’s far tougher.
With Flex, we keep the look—and raise the bar.
Preserve Sightlines Without Sacrificing Performance
Sightlines are sacred in heritage work.
That’s why the Flex Series offers slim profiles that honor the original design.
But behind that elegance?
You’ll find:
- High thermal insulation
- Excellent acoustic ratings
- Large glazed openings
- Dual weather-stripping
Your building looks old—but feels new.
Made to Order, Just Like the Original
Every window is made in our New York facility, custom to your specs.
We match profiles, finishes, colors—even operation style.
Whether it’s a double casement, fixed frame, or oversized door, we engineer each piece to maintain the look and feel of the original.
And we’ll work with your architects and preservation experts every step of the way.
The Look of Yesterday, The Technology of Tomorrow
We’ve combined traditional style with 21st-century tech:
- Zinc-rich epoxy primers
- Electrostatically applied powder coatings
- Optional monolithic glazing
- Custom color matches, including non-metallic options
This is how you make a statement in a historic neighborhood—without drawing the wrong kind of attention.
Flex Steel in Action
You’ll find our Flex Series in heritage renovations across the U.S.—from repurposed factories in New York to historic schools in Chicago.
They’re strong.
They’re accurate.
And they last.
Let’s Bring Your Restoration to Life
Heritage projects demand care, precision, and craftsmanship.
That’s exactly what we deliver with the Flex 6500SB Series.
Contact us and tell us your building’s story—we’ll help you write its next chapter.
Steel windows for heritage buildings start with Flex.
