https://unfoldo.com/blog/Articles on laying out sheet metal parts: flat patterns, thickness, seams, press lines and cutting, written for fabricators.en Thu, 05 Nov 2026 09:00:00 GMT https://unfoldo.com/blog/sheet-thickness-in-flat-patterns/https://unfoldo.com/blog/sheet-thickness-in-flat-patterns/Thu, 05 Nov 2026 09:00:00 GMTLay out rolled and formed parts on the mean line, the middle of the sheet, because that layer keeps its length. For a cylinder the mean diameter is the inside diameter plus one thickness. Each layout mistake costs π × t on the blank: 15.7 mm for 5 mm plate. https://unfoldo.com/blog/square-to-round-flat-pattern/https://unfoldo.com/blog/square-to-round-flat-pattern/Thu, 05 Nov 2026 09:00:00 GMTA square to round is laid out by triangulation: four flat triangles on the sides and four corner pieces, each split into thin triangles from the corner of the square to points on the circle. Every line's true length is √(plan length² + height²); the triangles are then drawn one after another on the sheet.