How to save blocks for use in other part sketches.
Open any part file and create a block in a sketch. Save the part file.
Open a new part file and start a sketch. Go to the Feature Library tab and browse to the file you created your block in.
Select the part. The block you created in this part will be listed in the lower pane of the Feature Library.
The block can then be dragged into the sketch.
Likewise, you can browse to and select any part file containing block(s) from the Feature Library tab and re-use them.
Notes