Built me a new tool

How much weight do they hold per tire? TBH, i dont think it's very much. I think trying to put a K frame with engine and trans on these is going to be too much for them. My wagon that has 4 of these very wheels I have loaded with 100 lb bags of blast media, it could barely hold the weight on one 100LB bag of glass media. Your going to ask them to carry about 900 lbs