Booleans are a common operation in any CAD system. Let’s take a look at how we handle booleans in Onshape.

You’ll find the Boolean command in the Part Studio toolbar:

The Boolean command has three options: “Union,” “Subtract,” and “Intersect.” The “Union” option is useful if you want to merge multiple solid parts into one. Simply select all the parts you want to merge and they will be brought together to form one.

The second boolean option, “Subtract,” allows you to subtract a part or parts from another one. This is a common technique in many different industries, such as mold making, where the first step in the process of creating a mold is subtracting a finished part from a cavity or core.

Another useful technique for the “Subtract” option is multi-part modeling. By subtracting one part from another, you can ensure the two (or more) have a perfect fit.

The “Subtract” option in the Boolean command includes an “Offset” option. This is useful if you want a small amount of clearance between the parts in your boolean.

The final boolean option, “Intersect,” will leave you with only what is intersecting between the parts you select. So if you need a way to remove everything except what is shared between certain parts, use the Intersect option.

One final note: Many Onshape commands have built-in boolean functionality. Commands like Extrude, Revolve, Sweep, Loft, Patterns, and others all have settings at the top of the dialog that allow you to set boolean options.

So in many cases, a separate boolean step is no longer necessary!

Interested in learning more? Watch the video at the top of this post.