Best coupler / adapter for propeller attachment to standard propeller

Hi all,

Years ago I created DIY kits on my own as a classroom set for STEM. I’m doing this again at a new school, and can’t find the store where I purchased, specifically, the coupler / adapter for connecting propellers to standard bilge replacement motors. Ideally, I would buy a kit of the couplers and propellers to keep things easy.

My question is - what is the best coupler/adapter out there now? There was an old aluminum one that I used to buy and would not stay on well. The newest one they offered was more reliable. Links please, and thank you!


These are made of solid brass, but the grub screws are made of steel, but if you paint the screws it will last longer I guess…

Best Regards