To create a library feature, you first create a base feature to which you add the features that you want included in the library feature. Library features have the .sldlfp extension. You can also have a sketch as a Library feature.
Note: You cannot create a library feature part from a multibody part document and also cannot create sheet metal parts, weldments, or molds, and save these as library features
To create a library feature that includes references, you need to dimension the library feature relative to the base part on which you create it. References create dimensions used to position the library feature on the model.
To create a library feature without references, create the library feature without dimensions or relations relative to the base part. Instead of using references to position the library feature on the model, you edit the library feature sketch and position that sketch relative to the model.
To create a library feature:
1. Create a sketch as shown in the image below. (Here the origin is used as the locating feature so each time we want to drop the rectangle it’s going to ask for a point). After the sketch is done exit the sketch and with the sketch highlighted in the Feature tree (shown in red rectangle), Select, File - Save as and select Library Feature Part (shown in red rectangle) as the file type and save it to the Design Library Directory.
Note: You can save it to another Folder and then add that Folder to the Design Library using the Add File Location as shown below.
2. If the sketch is saved correctly then the icons shown in the image below will appear automatically.
3. Now you can open the Design Library from the Task Pane as shown in image below and our sketch should be there.
4. Now create the feature you want and then simply drag and drop the sketch on the desired face and locate it with the locating dimension or relations (in our case it’s going to be origin) as shown in the image below.
5. Now you can see the sketch and then if you want you can apply the desired feature as shown below.
Note: The same procedure applies if you want to save a Feature as a design Library Feature.