Take a cylinder and punch a centered circular hole through it--like a washer. What is that shape called? In 2D it's an annulus, but what's the name of its 3D equivalent?
Also, what is this shape called when you remove part of it along 2 radii?
2 Answers
$\begingroup$In a sphere it's a spherical ring. If the remainder of the cutout is round it's a donut or toroid but Wikipedia shows a square toroid too. English.SE has a dozen answers, depending on usage.
$\endgroup$$\begingroup$Nothing hard and fast, depends on local industry usage or custom.
Some suggestions
First image
Thick cylinder
Thick hollow cylinder
Flat Ring Blank
Second image
Prismatic punched sector
Thick Prismatic annular sector
Thick punched sector
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