“Test Club” is the generic name given to a propeller used for ground running and bench testing purposes. They are essential when running an aircraft engine (especially on air cooled engines) as they provide both essential loading to the engine and also cylinder head cooling. They can also be sized and pitched so that the engine under test cannot exceed its rated rpm or for a specific performance curve.
Occasionally the aircraft propeller itself can be used as a test club (Often a cropped version of) but a test club cannot be used as an aircraft propeller.
As you can imagine that makes things far rarer than aircraft propellers themselves as they are only really used by aircraft engineers.
We’ve been lucky enough to acquire these set of 5 and they’re the only wooden ones we’ve ever come across, we believe there from around the 40s and 50s.
Selling individually, these would make a very unique talking piece and would look fantastic in any setting.