For this size Blast nozzle here is the size and the air required for best performance

NO.750 NOZZLE BORE-7/16″/11.0mm
LENGTH – 205mm
Thread Size-50mm
Inlet Size-32mm
Air Requirement-254/350 CFM
Horsepower-hp/(kW) 60/(44.74)

THE AIR REQUIREMENT IS TO ACHIEVE 100 psi AT THE NOZZLE