Thread: 50mm tow balls

50mm ball is very common
Higher rating for a start.

There are new duofit couplings out that can fit 50mm and 1 7/8" balls
https://trojan.co.nz/Duofit-Coupling...-9b75491e9f30/
https://trojan.co.nz/COUPLING-V2-250...-f1ff6d501f82/
https://trojan.co.nz/Duofit-Override...-69d7ec1488aa/
https://trojan.co.nz/Duofit-Override...-5d3fb3959927/

trailer, boat, caravan, all of mine use 50mm. I think NZ is the only place that uses 1 7/8

Originally Posted by cambo

50mm ball is very common
Higher rating for a start.

1 7/8" & 50mm have the same rating. Its not the ball diameter that determines the rating, its the threaded shank size that does that. 3/4" shank is usually 2000kg and the 3500kg is 7/8" or 1" shank. The 7/8" is usually a heat treated steel to increase tensile strength to handle the load.