Propeller Replacement Propeller Dia (In.) 24 in Bore Dia (In.) 3/4 in Number of Blades 4 Pitch (Deg.) 19 Degrees Blade Material Spark Resistant Cast Aluminum Keyway (In.) 3/16 in W and 3/32 in D Number of Set Screws 2 Rotation CW Facing Discharge Required Motor HP 3/4 Required HP @ Higher RPM - RPM Low - RPM High - Max RPM 1725 CFM @ 0.000-In. SP 6720 CFM @ 0.125-In. SP 6030 CFM @ 0.250-In. SP 5445 CFM @ 0.375-In. SP 4 655 cfm CFM @ 0.500-In. SP 3 900 cfm