Abstract: An instrument mounting apparatus includes a bracket into which the instrument is inserted, a washer which slides over the instrument and dimensioned to hold the instrument, and a nut which also slides over the instrument. The bracket has key slots for accepting keys extending from the washer and has threads on the outer surface which mate with threads on the inner surface of the nut. Radial slots in the nut permit the insertion of a rod for torquing the nut tight to the bracket, while tapped channels are provided for a inserting a set screw into the one most convenient.