Splitting crafted parts?

Not sure what your question is but yes you can split the parts that you have already made. Go to the Parts factory and select the Depot option to see your parts and materials. Select the Part tab at the top and then find there all the parts you have. If the parts are equipped on a vehicle you will need to unequip them first. Then you will have an option to split them. You will get back the materials that you used to make them.