What is the size of the end nut holding the bar cover on my SWJ803E? The end nut beneath the end nut cover that holds the bar cover on to your unit is a size 13mm metric flange hex nut. Any 13mm socket or spanner wrench will be able to remove or tighten this end nut. Related articles What chain does my SWJ800E use? How do I assemble my SWJ800E? How do I assemble my SWJ802E? How loud is my Saw Joe SWJ803E? How do I clean debris/residue from inside the unit?