Is the RM - M30/ Ref: 264-44-12 lifting eye nut suitable to use on chemically fixed threaded bar and does it have a 4mm thread?

Yes the RM eyenut can be used with chemically fixed threaded bar but must meet the below criteria:

1.        Threaded bar must be of minimum class 8.8 and be crack detected by the manufacturer
2.        The threaded bar must be secured, and the chemical bonding must have cured prior to the eyenut being fitted
3.        The eyenut must be fully seated on the load

The thread is ISO metric M30 x 3.5

We can only confirm the integrity of the eyenut and not the fixing.