You have several clipping masks there; the lead tip, the tapered naked wood, and the eraser.
Go back to the original state and Ungroup if necessary, then select just one masked object at a time and use the Pathfinder > Crop function to apply and eliminate each respective clipping mask. (You won’t see a visible change on the artboard, but Layers panel shows the difference.)
Click on the eraser shape to select the masked object.
Click the Crop button in the Pathfinder panel.
This will “crop” the underlying object to the confines of the mask and leave just the new, mask-shaped object.
Repeat individually for the other masked objects.
After that, you’ll get a more viable result from your Expand operations.