DALTON (R20T27)

Description

Dalton perforated sheet metal Dalton R20T27 promotes high air/light exchange with direct and consistent visual readability. It is composed of Ø 20 mm round holes, arranged in a staggered pattern (triangular grid) with a pitch of 27 mm. With the designation Rv20-27, this geometry provides approximately 50% transparency (opening area ≈ 314 mm² for a triangular mesh ≈ 632 mm²), which is ideal for intense ventilation, visually lightening spaces, and creating soft shadow effects. The staggered pattern distributes the openings evenly, with no preferred direction: from a distance, the skin appears homogeneous and breathable; up close, the 20 mm perforated circle forms a spacious and contemporary dotted pattern that is highly legible, making it suitable for breathable technical facades, machine box screens, HVAC covers, cladding boxes, and secondary cladding when the aim is to maximize air flow while maintaining a simple graphic design for the building's facade. With T = 27 mm and Ø = 20 mm, the "in-line" ligature is 7 mm, making this triangular perforation pattern easy to read. The center-to-center distance between rows is ~23.4 mm (√3/2·T), which leaves a minimum ligature of approximately 3.4 mm in the most stressed oblique direction. This reduced ligature requires precautions: • for 1.5 mm steel, limit the size of unframed panels (rather modest unit sizes); • favor welded/bolted peripheral framing and/or stiffening folds; • for longer spans, exposed areas (wind, impact, vibration) or intensive use, aim for 2 mm or even 3 mm thickness, steel with a higher elastic limit. However, T-perforation distributes stress well in both axes, which, combined with a suitable frame, ensures reliable performance. The 20 mm openwork aperture provides genuine airflow and generous light diffusion. Made of 1.5 mm thick galvanized steel, Dalton R20T27 perforated sheet metal generally costs between €55 and €80/m² for an order of around 100 m², depending on thickness, finish, layout, stiffeners/frames, and installation constraints.

Uses

R20T27 – Dalton perforated sheet metal Dalton defined by its perfect balance between mechanical strength and visual openness. With its 20 mm round holes arranged in a staggered pattern and a void ratio of nearly 50%, it offers clear transparency without weakening the material. This universal perforated sheet metal is ideal for applications where the sheet metal must protect, ventilate, and interact with light: facades of public buildings, parking garage enclosures, exterior railings, ventilated technical rooms, or decorative fences. Its regular pattern provides a sense of order and continuity, without excessive density or voids. When used outdoors, R20T27 perforated sheet metal resists mechanical stress while allowing air and light to pass through freely. The balanced ratio between solid and open areas ensures good wind resistance, prevents warping, and guarantees the rigidity of the panels over long spans. This classic round perforation, proven in both industry and architecture, combines technical efficiency with aesthetic simplicity. With almost 50% open area, R20T27 perforated sheet metal promotes effective natural ventilation. It is ideal for technical cladding (sheathing, machinery, ventilated rooms) and privacy screens where air circulation must remain constant. The staggered arrangement creates a rhythmic, continuous pattern and soft light diffusion. The R20T27 – Dalton perforated pattern Dalton understood as a grid of precision. Each opening is measured: neither too much nor too little. The balance of solids and voids creates a reliable, reassuring, naturally geometric material. Architects find it a stable module that is easy to lay out over large surfaces. Metalworkers see it as a versatile, robust, and easy-to-work-with perforated sheet metal. Interior designers see it as a clear, open facade texture capable of interacting with natural or artificial light.

Team advice

For an optimized range/price ratio, we recommend DALTON sheet metal DALTON Galvanized steel, thickness 1.5 mm