Mold Design – Creating a simple core and cavity

We are going to understand the basics of mold tool in SolidWorks.

In this step by step demonstration will be given to create core and cavity of the following part.


First thing to do is to locate the mold toolbar


In mold tools click on scale, and scale the part to 2%. Just to allow some shrinkage that could happen.

1.02 scale factor means 2% scaling.

Make sure that ‘scale about’ is set to centroid for uniform scaling.


Next thing we need to do is describe the parting line of our model.

To do this, go to parting lines tool.


Parting lines tool gives a line between positive and negative draft.

This tool analysis 4 types of drafts.

  1. Positive
  2. Negative
  3. Zero or nil draft
  4. Both positive and negative draft

This is the menu for parting lines tool, first thing to do to find out the parting lines is to specify the pull face, here front plane is selected.

Next, click on draft analysis.


These are the results of analysis performed.

  • In this, green represents positive draft
  • Yellow represents zero draft
  • Red represents negative draft
  • blue represents both negative and positive drafts.


Parting lines are given below the color specification.

Click ok.


Next thing to do is to close the holes from our model.


We have to do this because holes in the model will let cavity and core pass through which is not required, cavity and core should be separated by the original model.

To fill out the holes, shut-off faces is used.


This is pretty simple task to perform.

It automatically finds different holes in the model, all the user has to do is to click ok, and all holes in the model are filled.

Make sure that knit, filter loops and ‘show callouts’ are checked before clicking ok.


This is the model after filling all the holes.

There is a difference in color because two surfaces are formed simultaneously.

The red rectangle represents the 2 surfaces which are causing two colors to appear.

These surfaces are core and cavity of the model.


Next let’s model parting surface.

Click on parting surface and select the parting line previously created and click ok.


Set the parting surface length. Here, 6”.

Also set the direction of surface.

Here, direction is perpendicular to pull.

Make sure that knit all surface is selected.


Model with parting surface.


Next click on tooling split tool.


This tool splits a solid from a surface.

In this example we will use parting surface as the surface to split.

Draw a profile which will decide the shape of core’s and cavity’s outer shape.

Image-16Image-17The finished core and cavity after tool splitting.


To check whether cavity and core are created or not, go to exploded view.

Contact us for more information and help on mold tool in SolidWorks at or call 03 86770871