While most spanner wrenches have either 2 holes or pins. I made this one many years ago for assisting in tightening the flange on differentials.
I hadn't posted it before because 1 I had forgotten all about it and 2 the need to use it had not arrived until this week.
the Spanner is a simple 3 piece weldment of flat bars with a single hole drilled in it I use 1 of the flange bolts to bolt it on with and another to push against. when removing or installing the flange Mostly just for installing since removing can be easily done with an impact wrench. For install it is required because the bearing preload must be set by a breaker bar and socket.
the construction of the spanner allows for a wide range of adjustment. And yes a simple straight bar with a hole in it would work just as well