Pololu Universal Aluminum 5mm Mounting Hub (4-40)

I had trouble finding this style flat hub but found it here. Great quality and delivery. Liked that the Allen wrench and screws were included.

Dont like price, but is a very good product, must have

Great product. Used it to mount a motor and increased the motor's strength immensely. Cheap shipping to Hawaii too.

Parts were exactly as expected. The quality was great and the threaded holes on the hubs seem strong enough even though the part is very light weight. And I can't forget to mention RoboShop's amazingly fast delivery.

Great for what they are, but I made the mistake of buying these for a motor with a smooth shaft (not a D-shaft). If you're in the same boat, I'd strongly suggest going for a clamping shaft such as this one: https://www.robotshop.com/ca/en/actobotics-5mm-bore-077-aluminum-clamping-hub.html These are made by Servocity (USA), but international shipping to Canada is expensive ($25), so you're better off buying them here.