I know that a 2-dimensional rectangle that has semicircular ends instead of flat ones is called an 'obround' or a 'stadium', but what is the name of a three-dimensional rectangular cuboid that has semicircular, and not flat, edges, like the one in this photo? Is 'obround cylinder' an appropriate name?

enter image description here

  • Welcome to GD.SE!
    – Mensch
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  • The 2D shape is also known as a racetrack, in many cad applications
    – joojaa
    Commented Nov 30, 2021 at 9:30

1 Answer 1


I have seen a patent description which says "obround extrusion" It's this https://patents.google.com/patent/EP2149663A1/en. At least it was understood in 2008. The shape is part number 20.

The same shape in the patent was also described as oblong with rounded ends in the cross-section. "Oblong" in that place means that it's taller than wide.

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