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extrusion

ik-STROO-zhuhn /ɪkˈstruːʒən/

nounC1GRE

technicalprofessional

A manufacturing process or CAD feature where a 2D profile is pushed or pulled through space to create a 3D solid with a constant cross-section.

In CAD, extrusion is the most fundamental way to turn a flat 2D sketch into a 3D object by giving it depth along a straight path.

The story behind the word. From the Latin 'extrudere', combining 'ex-' (out) and 'trudere' (to push or thrust). Originally used in the 16th century to describe physically forcing someone out of a place. In the 19th century, it became a metallurgical term for forcing hot metal through a die, and in the 1980s, it became a core CAD command.

Word relationships

projection: Projection is a general geometric term for extending a shape, while extrusion specifically implies creating volume with a constant cross-section.
protrusion: Protrusion is something that sticks out, whereas extrusion is the specific process of creating that shape by pushing material.

intrusion: An intrusion is a forcing in, or in CAD, a cut or pocket that removes material rather than adding it.

Commonly confused with

revolution: Revolution creates a 3D shape by spinning a 2D profile around an axis, while extrusion pulls it in a straight line.

Word family

extrude (verb): To thrust or force out, or to shape material by forcing it through a die.
extruder (noun): The part of a 3D printer or machine that pushes material out.

Collocations

aluminum extrusion
extrusion process
extrusion die
linear extrusion

Example sentences

"To create the aluminum window frame, the factory used an extrusion process to push hot metal through a shaped steel die." A design guide explaining how aluminum profiles are manufactured.

Memory hook

Think of squeezing toothpaste out of a tube. The toothpaste takes the circular shape of the nozzle and forms a long, continuous cylinder—that is extrusion! Extrude to push it out.

When not to use

Do not use when describing complex, organic shapes that require lofting, sweeping, or sculpting rather than a simple linear projection.

Fun facts

Play-Doh fun factories are classic examples of extrusion machines; you push the clay through a plastic template to make stars, spaghetti, or clover shapes.

Related words

mesh, parametric, constraint

Explore more words

propulsion, render, carve, manufacturing, cam, production