For sale is a matching pair (LH / RH) of NEW four bladed boat propellers. They are made by Mencast. Diameter is 508mm (20”) Pitch is 415mm (~16.4)
The shaft hole tapers from 1.573” x ~1.870”. That works out to 40mm x 47.5mm. Measuring the larger side of the taper gets a little trickier so I suspect it’s probably 48mm.
I have 3 props total: 2 that are right hand and 1 left hand. All other dimensions are the same. See pics for further specs.