Trailer bearing question

Are you planning on using that tool to remove your dust caps, on the axle assembly/hub?
If so, you should only need a rubber mallet to tap the 1" shaft side to side, up and down, to break it free from the hub. Then a good hard tap, to the 1" extension, to replace the dust cap.
I’ve never seen dust caps threaded onto the hub?

I believe you fit the end of that tool to a hammer.

That tool is not intended to rotate. It’s a tap on and tap off kind of connection.

OK thanks.
that makes sense.