# How can I extrude a mesh whose thickness is 0?

**URL:** https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157
**Category:** Modeling Questions
**Created:** [January 22, 2025, 12:25am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157 "2025-01-22T00:25:28Z")
**Posts on this page:** 7
**Page:** 1

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### Author: ![Badam](https://avatars.discourse-cdn.com/v4/letter/b/bc79bd/32.png) [@Badam](https://discourse.shapr3d.com/u/Badam)
#### Post date: [January 22, 2025, 12:25am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/1 "2025-01-22T00:25:28Z")

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I have a mesh imported from STEP. Its thickness is 0. How can I extrude it to make it thick?

 ![IMG_0542](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/5/95e7eb3caf94de8e1e89d93c0085a6272d0e656f.jpeg)

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### Author: ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)
#### Post date: [January 22, 2025, 12:49am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/2 "2025-01-22T00:49:14Z")

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Select that surface and project it.

Projection will create a new sketch, use loft to make it solid.

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### Author: ![GroMark](https://avatars.discourse-cdn.com/v4/letter/g/4491bb/32.png) [@GroMark](https://discourse.shapr3d.com/u/GroMark)
#### Post date: [January 22, 2025, 5:06am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/3 "2025-01-22T05:06:27Z")

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You can also use a negative Shell feature, I think

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### Author: ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)
#### Post date: [January 22, 2025, 5:33am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/4 "2025-01-22T05:33:32Z")

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Actually you could just duplicated it and loft it.

 ![Screenshot 2025-01-21 at 9.29.39 PM](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/5/f/5f207f8c6a8672508ac1c5f5b52c5dc3f9c31ffa.jpeg)  
 ![Screenshot 2025-01-21 at 9.31.55 PM](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/e/2/e285a8cc95fdc9fbc1a9900bf498ef0c1464611d.jpeg)  
 ![Screenshot 2025-01-21 at 9.33.02 PM](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/5/a/5a0881d354f4f3aed990b3345d412aa59f1d23f8.jpeg)

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### Author: ![Badam](https://avatars.discourse-cdn.com/v4/letter/b/bc79bd/32.png) [@Badam](https://discourse.shapr3d.com/u/Badam)
#### Post date: [January 22, 2025, 8:52am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/5 "2025-01-22T08:52:54Z")

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That’s the best way, thank you.  
However, I have hundreds of polygons - is it possible to loft all of them at once? Do I have to select each pair individually?

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### Author: ![Badam](https://avatars.discourse-cdn.com/v4/letter/b/bc79bd/32.png) [@Badam](https://discourse.shapr3d.com/u/Badam)
#### Post date: [January 22, 2025, 8:54am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/6 "2025-01-22T08:54:09Z")

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Unfortunately Shell and negative Shell do not work.

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### Author: ![SCALEMODEL](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@SCALEMODEL](https://discourse.shapr3d.com/u/SCALEMODEL)
#### Post date: [January 22, 2025, 9:00am UTC](https://discourse.shapr3d.com/t/how-can-i-extrude-a-mesh-whose-thickness-is-0/36157/7 "2025-01-22T09:00:19Z")

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You can in Onshape, the feature is called Thicken. You can import the STEP file and apply Thicken. Personal Hobby work is free but if that is an issue.

Freecad can do it, [How to add thickness to a surface? - FreeCAD Forum](https://forum.freecad.org/viewtopic.php?t=16546)

Side note, Shapr is not a surface modeler, it doesn’t know what to do with that kind of import when thickness is 0. 3d Model Imports should be 3 dimensional solid.