How to use
For rings choose outside/bore diameters and optional bolt holes; bore 0 makes a disc. For plates enter grid counts, pitches and first-centre offsets; download SVG/DXF.
Example calculation
D = 300 mm; d = 180 mm; n = 0 → A ≈ 0.04523893 m².
Calculation method
○: A = π(D²−d²)/4 − nπdh²/4 ▭: A = WH − nr × nc × πdh²/4 X = x₀ + i × px; Y = y₀ + j × py
Calculation limits
2D geometry only, not a flange standard or pressure rating. Up to 200 ring holes or 400 plate holes. Holes cannot touch edges or overlap; DXF units are mm.