Pacific Roll LLC

Cone Flat Pattern Calculator

Enter the small OD, large OD, vertical height, and material thickness of a concentric cone — get the exact flat pattern sweep angle, inner and outer radii, and arc lengths with a visual layout diagram.

Units (length)

Cone Dimensions

All four values are required. Large OD must be greater than Small OD.

Small OD (in)

Outside diameter of the small (top) end

Large OD (in)

Outside diameter of the large (bottom) end

Vertical Height (in)

Perpendicular height of the cone (not slant)

Material Thickness (in)

Plate thickness — offsets the flat pattern radii

Share on LinkedIn Request a Quote

How to Use

1.
Select your unit of measurement.
2.
Enter the Small OD — the outside diameter of the narrow (top) end of the cone.
3.
Enter the Large OD — the outside diameter of the wide (bottom) end.
4.
Enter the Vertical Height — the perpendicular distance between the two ends (not the slant).
5.
Enter the Material Thickness — the plate thickness used to offset the flat pattern radii.
6.
The flat pattern diagram and all layout dimensions calculate instantly.
7.
Use Print / Save PDF to export a results sheet for the shop floor.

Definitions

Small OD

Outside diameter of the narrow end of the cone.

Large OD

Outside diameter of the wide end of the cone.

Vertical Height

Perpendicular distance between the two circular ends — not the slant height.

Material Thickness

Plate thickness. Used to offset the flat pattern inner and outer radii from the theoretical centerline.

Half Angle

Angle between the cone axis and the slant surface. Determines how much the flat pattern radii are offset by the thickness.

Slant Height

Distance along the cone surface from apex to a circular end. The flat pattern radii are derived from these values.

Sweep Angle

The included angle of the flat pattern sector. A full cylinder would be 360 deg; a steep cone will be much less.

Outer Radius

Flat pattern radius to the outside face of the large end — the largest dimension on the flat blank.

Inner Radius

Flat pattern radius to the inside face of the small end — the smallest dimension on the flat blank.

Arc Length

Length of the curved edge on the flat pattern. The outer arc length should match the large end circumference after forming.

Need a cone rolled or fabricated? Pacific Roll specializes in precision plate rolling and cone fabrication for structural and architectural steel projects.