Extruded surface in Solidworks - Step-by-Step Guide

Introduction

An extruded surface in SolidWorks lets you create a thin, flat shape by stretching a 2D sketch in one direction. This helps you model parts that need surface details without making them solid, saving time and resources.

When you want to add a thin wall or cover to a part without making it solid

When creating a surface to use as a reference for trimming or splitting other parts

When modeling complex shapes that require surface features before thickening

When you need to analyze or visualize only the outer shape without internal volume

When preparing a model for surface-based operations like knitting or patching

Steps

Step 1: Click

- Features tab > Extruded Surface button

The Extruded Surface property manager opens on the left side

💡 Make sure you have a 2D sketch selected or ready before starting

Step 2: Select

- Sketch in the graphics area or FeatureManager design tree

The sketch profile highlights and appears in the property manager

💡 Use a closed sketch for a clean surface; open sketches create open surfaces

Step 3: Enter

- Depth box in the property manager

The preview shows the surface extruded to the specified depth

💡 Use positive values to extrude outward, negative to extrude inward

Step 4: Choose

- Direction 1 options (Blind, Through All, Up to Vertex, etc.)

The extrusion direction and extent update in the preview

💡 Blind is the most common for fixed depth extrusion

Step 5: Click

- OK (green checkmark) button

The extruded surface feature is created and appears in the FeatureManager

💡 You can edit the feature later by right-clicking it and selecting Edit Feature

Before vs After

Before

A 2D closed sketch of a rectangle on the front plane

After

A thin rectangular surface extruded 10 mm outward from the sketch plane

Settings Reference

Direction 1

📍 Extruded Surface property manager

Controls how far and where the surface extrudes in the first direction

Default: Blind

Depth

📍 Extruded Surface property manager

Sets the distance the surface extends from the sketch plane

Default: 0.01 (default minimum)

Thin Feature

📍 Extruded Surface property manager (checkbox)

Creates a surface with thickness instead of a simple surface

Default: Unchecked

Common Mistakes

Trying to extrude a surface from an open sketch

Open sketches create open surfaces that may not behave as expected in later operations

Close the sketch by connecting endpoints before extruding the surface

Confusing extruded surface with extruded boss/base

Extruded boss/base creates solid bodies, which may increase file size and complexity unnecessarily

Use extruded surface when you only need a surface without volume

Summary

Extruded surface stretches a 2D sketch into a thin surface shape.

It is useful for modeling thin walls, references, or surface details without solids.

Always use closed sketches for clean surfaces and choose the right extrusion depth and direction.

Practice

1. What is the main characteristic of an Extruded Surface in SolidWorks?

easy

A. It creates a thin 3D shape without volume.

B. It creates a solid 3D object with volume.

C. It only creates 2D sketches.

D. It automatically adds thickness to a solid.

Solution

1. Step 1: Understand the definition of extruded surface

   An extruded surface stretches a 2D sketch into a 3D shape but does not create volume.

2. Step 2: Compare with solid extrusion

   Unlike solid extrusion, extruded surfaces are thin and have no volume.

3. Final Answer:

   It creates a thin 3D shape without volume. -> Option A

4. Quick Check:

   Extruded surface = thin 3D shape without volume [OK]

Hint: Remember: surfaces have no volume, solids do [OK]

Common Mistakes:

• Confusing extruded surface with solid extrusion
• Thinking extruded surfaces add thickness automatically
• Assuming extruded surfaces are 2D only

2. Which of the following is the correct syntax to create an extruded surface in SolidWorks using the feature tree?

easy

A. Right-click sketch > Select 'Extruded Surface'

B. Right-click sketch > Select 'Extruded Boss/Base'

C. Right-click sketch > Select 'Revolve Boss/Base'

D. Right-click sketch > Select 'Cut-Extrude'

Solution

1. Step 1: Identify the correct feature for extruded surface

   The feature to create an extruded surface is called 'Extruded Surface' in SolidWorks.

2. Step 2: Eliminate other options

   'Extruded Boss/Base' creates solids, 'Revolve Boss/Base' is for revolved solids, and 'Cut-Extrude' removes material.

3. Final Answer:

   Right-click sketch > Select 'Extruded Surface' -> Option A

4. Quick Check:

   Extruded surface feature = 'Extruded Surface' [OK]

Hint: Look for 'Surface' keyword in feature name [OK]

Common Mistakes:

• Choosing 'Extruded Boss/Base' which creates solids
• Confusing revolve features with extrusion
• Selecting cut features instead of surface creation

3. Given a 2D sketch of a circle with radius 10mm, what will be the result of applying an extruded surface with a depth of 5mm?

medium

A. A solid cylinder with radius 10mm and height 5mm

B. A flat 2D circle with no thickness

C. A thin cylindrical surface with radius 10mm and depth 5mm

D. A hollow sphere with radius 10mm

Solution

1. Step 1: Understand extrusion of a circle sketch as surface

   Extruding a circle sketch as a surface creates a thin cylindrical shell, not a solid.

2. Step 2: Analyze the depth parameter

   The extrusion depth of 5mm defines how far the surface extends in 3D space.

3. Final Answer:

   A thin cylindrical surface with radius 10mm and depth 5mm -> Option C

4. Quick Check:

   Extruded surface of circle = thin cylinder surface [OK]

Hint: Extruded surface keeps shape but no volume [OK]

Common Mistakes:

• Assuming extrusion creates a solid cylinder
• Thinking extrusion does not add depth
• Confusing surface extrusion with 2D sketch

4. You tried to create an extruded surface but the feature failed. Which of these is the most likely cause?

medium

A. The extrusion depth is set to zero.

B. The sketch is fully defined.

C. You selected 'Extruded Boss/Base' instead of 'Extruded Surface'.

D. The sketch is not closed.

Solution

1. Step 1: Check sketch closure

   An extruded surface requires a closed sketch; an open sketch will cause the feature to fail.

2. Step 2: Review other options

   Zero extrusion depth causes no extrusion but usually does not cause feature failure; selecting wrong feature changes output but not failure; fully defined sketch is good practice and does not cause failure.

3. Final Answer:

   The sketch is not closed. -> Option D

4. Quick Check:

   Open sketch = feature failure [OK]

Hint: Ensure sketch is fully closed before extrusion [OK]

Common Mistakes:

• Ignoring open sketch as failure cause
• Confusing zero depth with failure
• Assuming fully defined sketch causes failure

5. You want to create a thin cover part by extruding a rectangular sketch 2mm as a surface, then offset it by 1mm to create thickness. Which sequence of features should you use?

hard

A. Extruded Surface (2mm) -> Thicken (1mm)

B. Extruded Surface (2mm) -> Offset Surface (1mm) -> Thicken

C. Extruded Boss/Base (2mm) -> Shell (1mm)

D. Extruded Surface (2mm) -> Cut-Extrude (1mm)

Solution

1. Step 1: Create the base thin surface

   Use 'Extruded Surface' with 2mm depth to create the initial thin surface.

2. Step 2: Offset the surface to create thickness

   Apply 'Offset Surface' by 1mm to create a parallel surface at the desired thickness.

3. Step 3: Use 'Thicken' to convert surfaces into a solid with thickness

   Thicken the offset surfaces to form a solid cover part.

4. Final Answer:

   Extruded Surface (2mm) -> Offset Surface (1mm) -> Thicken -> Option B

5. Quick Check:

   Surface extrusion + offset + thicken = solid cover [OK]

Hint: Use offset and thicken after surface extrusion for thickness [OK]

Common Mistakes:

• Using solid extrusion instead of surface extrusion first
• Skipping offset surface step
• Using cut-extrude which removes material