Shank Style Trailer Balls
Match the shank diameter to the hole in your ball mount. The hole in the ball mount should not exceed the shank diameter by more than 1/16". Also make sure that the shank is long enough to cover the thickness of the ball mount and leave enough room to safely attach nut with lock washer. At least one thread should show below the nut.
As a general rule:
- 3/4" diameter ball shanks fit Class II ball mounts
- 1" diameter ball shanks fit Class III ball mounts
- 1-1/4" diameter ball shanks fit Class IV & V ball mounts