Does propeller material or ISO class affect my choice of thrust and power factors?
Material and class have no real impact on thrust and power factors (i.e., the Kt and Kq multipliers in NavCad, T & P factors in PropExpert and SwiftCraft). These are used to correlate thrust and power performance principally for the differences of geometry between your propeller design and a standard series design (such as the Gawn or B-series). For example, if you were to build a true Gawn propeller, the thrust and power factors would be 1.0 (i.e., no correction). However, if the geometry were different from the tested series propeller (as we typically see with the relatively heavier blade and edge thickness on commercial propellers), the factors would be adjusted to reflect the change in thrust and torque that you see in the the real world. You could make the argument that there needs to be some correction for propellers of less precise ISO classes. Assuming that the original propellers which made up the series were of high precision (which is to be expected for a laboratory model),
