Hi Gary, this wheel has the tread width of 3 1/8".
Hi Leo - The dimensions of the plate are 3 7/8" X 4 1/2".
SDF, thank you for your question. These casters are designed to withstand extreme temperatures and rough terrain. They should resist rust being outside year round.
Center to center these mounting holes are 3-1/2" x 3"
Hi Shepherd Product Guy, 50 PSI? Really? Sidewall on the tires say 30. Also, do these have tubes inside? Thanks!