Hit up Grainger.com and search for: HVACR - Fan Blades and Propellors - Aluminum Fan Blades

I think just searching Aluminum Fan Blades will pull it all up. Can narrow the search by diameter.

Here's a few fan blades from Grainger.com.

10" diameter, 1/4" hub hole, # 4C479 $8.37

10" diameter, 5/16" hub hole, # 2UJU2 $7.79

10" diameter, 5/16" hub hole, thicker aluminum, # 2MXY3 $16.82


I'm sure if you ask any machine supply shop or mechanical shop around town, they'll help you out. For example, MSC, J&L Industrial, McMaster-Carr, MacNoughton and McKay, Production Tool Supply, they all stock these kinds of fans.

Or... hit Walmart and buy some 9" wire cage fans, and gut em for the blades!