jester-

Screw on type prop hubs are the most common on conversion motors. Most places (including myself) make hubs from t-6061 aluminum or better which is not that soft. Clean both ends with some alcohol and use some blue or red locktite and youll never have a problem. Have you ever machined a prop hub??? If so , you would realize that someone selling one for $20 is BARLEY making any kind of profit on it.And to say that guys selling them for $20 are " out to make a quick 20 bucks " is just rediculious. Really.