OS2
75.
A precision roll-formed steel profile with a 75 mm frame depth and 27 mm sightline, joined by a dual polyurethane–polyamide thermal break — engineered for maximum thermal efficiency without compromising sightline purity. Fabricated in Italy by Secco Sistemi.
Performance
Narrow sightline.
Maximum envelope.
The OS2 75 separates interior and exterior frame halves with a composite non-conductive barrier — eliminating thermal bridging while maintaining the structural rigidity premium openings demand. A 27 mm sightline reads as classic Secco fenestration; a 75 mm depth carries triple-glazed insulating units to passive-house performance.
Anatomy
The profile,
broken thermally.
Roll-formed steel halves joined by a composite thermal break — pressure-infused polyurethane bonded to a polyamide strut. The dual-material core delivers structural rigidity and thermal isolation in a single section.
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01.
Italian-fabricated roll-formed steel — Secco Sistemi precision tolerances.
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02.
75 mm frame depth — accepts triple-glazed IGUs up to 50 mm.
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03.
27 mm sightline — the slimmest face in Secco's thermally broken family.
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04.
Composite thermal break — polyurethane + polyamide strut, structurally bonded.
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05.
Flipper gasket + double-overlap compression seal — weathertight in all climates.
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06.
Internal door striker seal — third compression point (acoustic + thermal).
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07.
U-factor as low as 0.18 — Title 24 compatible across California climate zones.
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08.
40+ profile sections — any formal requirement from window to bi-fold door.
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09.
Available in four metals — galvanized, stainless, corten, or solid brass.
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10.
Bi-material specifiable — different metals on interior and exterior faces.
Configurations
Two elevations.
One thermal core.
The OS2 75 is organized into two subsystems that determine how the facade reads from the exterior — each offering a distinct architectural language while sharing the same thermal core. Both subsystems support the full opening matrix: pivoting, tilt-and-turn, inward and outward casements, and doors.
Openable sashes are clearly legible in elevation. Glass panels are non-flush between sashes and fixed panels, and the central node of a double-leaf opening reads as a reduced, refined detail within the surrounding profiles.
Expressed SashOperable and fixed panels share regularly spaced nodes throughout the facade — making the difference between the two imperceptible from the exterior. Coplanar glass fixings create a flush, continuous glass plane.
Coplanar FlushGlazing Beads
Four profiles
of detail.
The bead is the smallest line in a steel window — and the one architects look at first. OS2 75 ships with four bead profiles, from the historically faithful Gothic to the razor-fine Thin. Each bead is produced in finishes that match the frame.
Materials & Finish
Four metals.
Bi-material specifiable.
The OS2 75 is available in four metals — each with dedicated finish options — and can be specified in Bi-material combinations, pairing different metals on the interior and exterior faces. Powder coating in any RAL is applied through Tiger Coatings, BlackFramed's certified European finishing partner.
vii. Specification
SpecifyOS2 75.
Whether you're an architect, builder, or homeowner, we'll review your project and prepare a custom quotation, preliminary specifications, finish options, and expected lead time.
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