We prefer wood - better airfoil, but for some folks these are faster to make and do just fine.

• Aluminum blades last longer than wood (usually).
• They don't need to be painted.
• You can make them with a BRAKE (roller) and sheet metal).
• They are noisy.
• They don't make as much power as a full profile blade of wood.
• But they don't mind stray birds as much as a wood blade does.