After studying many online, I sketched a single “blade” and spun a duplicate of it 180º. I took the pair and tried to duplicate it many times, but too many and it got complicated and confusing. Thus, I simplified it to eight.
The blade was made with a pair of overlapping circles, then nudged into basic shape with the Pen tool. The notches and groove were punched with outlined Strokes and the Shape tool. All of the blades have a Radial Gradient, Multiply Blend Mode, and Opacity set to 70%.