Rolling
Prepare a drawing for a rolled part
Dimensions and details that help roll sheet into a cylinder or curved part.
Reading time
5 min
Updated
15 October 2026
Category
Rolling
Rolling forms flat sheet into a cylinder, cone or curved section. To avoid guesswork, define the finished shape, reference dimensions and assembly requirements before preparing the flat pattern.
Define the finished geometry
State whether the part is a full cylinder, sector, cone or transition. Dimension the inside or outside diameter and height; for a cone, show both end diameters.
For a sector, specify its angle or arc length. Side and top views often resolve details that the developed length alone cannot show.
Distinguish diameter from radius
A diameter spans the part through its centre; a radius is half that value. State which one you use and the reference surface, especially when fit depends on the inside diameter.
For a part that fits over a tube or shaft, specify the desired clearance or fit and functional tolerances. Do not leave the workshop to infer a fit from an undimensioned sketch.
Specify material and surface requirements
Grade, thickness, sheet width and finish direction affect setup and the result. Mark visible faces, protective film and any surfaces the rolls must not mark.
Small diameters and conical transitions may need review against the material and equipment. Have the geometry and quantity checked before freezing the drawing.
Plan the edges and closure
Depending on how the rolls grip the sheet, the ends may remain flatter. If a consistent circle around the full circumference is essential, state this and ask how the ends will be corrected.
- State whether the edges meet, overlap or stay open.
- For a closed cylinder, specify weld length and the required finish.
- Mark holes, notches and cut-outs close to the closing edges.
- Define inspection dimensions after rolling and welding.
Plan how to inspect the part
Define the measurements that confirm the part will work: diameter, height, roundness, opening alignment or flange position. A clear inspection method and tolerance prevent disputes after fabrication.
Send a dimensioned drawing, a 3D model if available, thickness, material and quantity. For a new shape, approve a first part before the run to confirm fit and appearance.