8-32
1/2 X 1/2Rigid Shaft Coupling, Double Split AKA two piece type (qty 1)
A nice touch with Nordson is the availability of replacement parts when needed.
RELIABLE 8-32 MACHINE SCREWS, 1" PANHEAD, BOX OF 98, NIB
You will find that Reliable Aftermarket Parts Our Name Says It All is built to last through many cycles.